WorldWideScience

Sample records for convective loop houses

  1. Fuzzy logic controllers and chaotic natural convection loops

    International Nuclear Information System (INIS)

    Theler, German

    2007-01-01

    The study of natural circulation loops is a subject of special concern for the engineering design of advanced nuclear reactors, as natural convection provides an efficient and completely passive heat removal system. However, under certain circumstances thermal-fluid-dynamical instabilities may appear, threatening the reactor safety as a whole.On the other hand, fuzzy logic controllers provide an ideal framework to approach highly non-linear control problems. In the present work, we develop a software-based fuzzy logic controller and study its application to chaotic natural convection loops.We numerically analyse the linguistic control of the loop known as the Welander problem in such conditions that, if the controller were not present, the circulation flow would be non-periodic unstable.We also design a Taka gi-Sugeno fuzzy controller based on a fuzzy model of a natural convection loop with a toroidal geometry, in order to stabilize a Lorenz-chaotic behaviour.Finally, we show experimental results obtained in a rectangular natural circulation loop [es

  2. Dynamical behaviour of natural convection in closed loops

    International Nuclear Information System (INIS)

    Ehrhard, P.

    1988-04-01

    A one dimensional model is presented together with experiments, which describe the natural convective flow in closed loops heated at the bottom and cooled in the upper semicircle. Starting from a single loop, mechanical and thermal coupling with a second loop is discussed. The experiments and the theoretical model both concurrently demonstrate that the investigated natural convection is clearly influenced by non-linear effects. Beside the variety of stable steady flows there are extensive subcritical ranges of convective flow. In these parameter ranges subcritical instabilities of the steady state flow could occur in the presence of finite amplitude disturbances. However, the supercritical, global unstable range is characterized by chaotic histories of the variables of state. Non-symmetric heating generates an imperfect bifurcation out of the steady solution with zero velocity in the loop. This effect stabilizes the flow in the preferred direction. The flow in the opposite direction only remains stable in a small isolated interval of the heating parameter. Furthermore the calculations with the model equations demonstrate that a stable periodic behaviour of the flow is possible in a small parameter window. However, it has not been possible to verify this particular effect in the experiments conducted to date. (orig./GL) [de

  3. Stability characteristics of a single-phase free convection loop

    Science.gov (United States)

    Creveling, H. F.; De Paz, J. F.; Baladi, J. Y.; Schoenhals, R. J.

    1975-01-01

    Experiments investigating the stability characteristics of a single-phase free convection loop are reported. Results of the study confirm the contention made by previous workers that instabilities near the thermodynamic critical point can occur for ordinary fluids as well as those with unusual behavior in the near-critical region. Such a claim runs counter to traditional beliefs, but it is supported by the observation of such instabilities for water at atmospheric pressure and moderate temperatures in the present work.

  4. Heat transfer in a one-dimensional mixed convection loop

    International Nuclear Information System (INIS)

    Kim, Min Joon; Lee, Yong Bum; Kim, Yong Kyun; Kim, Jong Man; Nam, Ho Yun

    1999-01-01

    Effects of non-uniform heating in the core and additional forced circulation during decay heat removal operation are studied with a simplified mixed convection loop. The heat transfer coefficient is calculated analytically and measured experimentally. The analytic solution obtained from a one-dimensional heat equation is found to agree well with the experimental results. The effects of the non-uniform heating and the forced circulation are discussed

  5. Free convection in a partially submerged fluid loop

    International Nuclear Information System (INIS)

    Britt, T.E.; Wood, D.C.

    1982-01-01

    Several natural convection loop systems are studied in order to determine the operational characteristics for a multiple loop container which is used to cool failed nuclear reactor assemblies. Both analytical and experimental studies were undertaken to examine flow in both circular and rectangular flow loops. It was found that when a circular loop is heated at the bottom and cooled at the top, recirculation cells form at all input power fluxes. At fluxes between 0.1 W/cm 2 and 0.7 W/cm 2 the cells caused flow oscillations and reversals. With the circular loop heated from the side, no recirculation cells were observed at the power fluxes up to 1.5 W/cm. Boiling did not occur in the circular loop. For a rectangular loop heated and cooled on its vertical sides, no recirculation cells or flow reversals were seen. At input power fluxes above 1.2 W/cm 2 , periodic boiling in the heated side caused flow oscillations

  6. Closed Loop Recycling of Plastic Housing for Flat Screen TVs

    OpenAIRE

    Peeters, Jef; Vanegas, Paul; Devoldere, Tom; Dewulf, Wim; Duflou, Joost

    2012-01-01

    The treatment of the rapidly increasing number of End-of-Life (EoL) Flat screen Televisions (FTVs) presents major challenges and opportunities. Closing loops in plastic housing material flows remains a particular technical challenge because of the presence of additives, such as Flame Retardants (FR) in recovered housings. In the framework of a collaborative project PRIME with TP Vision the TV development site for Philips TVs and a Van Gansewinkel first level recycling plant, series of experim...

  7. Modeling a forced to natural convection boiling test with the program LOOP-W

    International Nuclear Information System (INIS)

    Carbajo, J.J.

    1984-01-01

    Extensive testing has been conducted in the Simulant Boiling Flow Visualization (SBFV) loop in which water is boiled in a vertical transparent tube by circulating hot glycerine in an annulus surrounding the tube. Tests ranged from nonboiling forced convection to oscillatory boiling natural convection. The program LOOP-W has been developed to analyze these tests. This program is a multi-leg, one-dimensional, two-phase equilibrium model with slip between the phases. In this study, a specific test, performed at low power where non-boiling forced convection was changed to boiling natural convection and then to non-boiling again, has been modeled with the program LOOP-W

  8. Mixed convection in a two-phase flow cooling loop

    International Nuclear Information System (INIS)

    Janssens-Maenhout, G.; Daubner, M.; Knebel, J.U.

    2002-03-01

    This report summarizes the numerical simulations using the CFD code CFX4.1 which has additional models for subcooled flow boiling phenomena and the interfacial forces. The improved CFX4.1 code can be applied to the design of boiling induced mixed convection cooling loops in a defined parameter range. The experimental part describes the geysering experiments and the instability effects on the two-phase natural circulation flow. An experimentally validated flow pattern map in the Phase Change Number - Subcooling Number (N PCh - N Sub ) diagram defines the operational range in which flow instabilities such as geysering can be expected. One important perspective of this combined experimental/numerical work, which is in the field of two-phase flow, is its application to the development of accelerator driven systems (ADS). The main objective on an ADS is its potential to transmute minor actinides and long-lived fission products, thus participating in closing the fuel cycle. The development of an ADS is an important issue within the Euratom Fifth FP on Partitioning and Transmutation. One concept of an ADS, which is investigated in more detail within the ''preliminary design study of an experimental ADS'' Project (PDS-XADS) of the Euratom Fifth FP, is the XADS lead-bismuth cooled Experimental ADS of ANSALDO. An essential feature of this concept is the natural circulation of the primary coolant within the reactor pool. The natural circulation, which is driven by the density differences between the blanket and the heat exchanger, is enhanced by the injection of the nitrogen cover gas through spargers located in a riser part just above the blanket. This so-called gas-lift pump system has not been investigated in more detail nor has this gas-lift pump system been numerically/experimentally confirmed. The knowledge gained within the SUCO Programe, i.e. the modelling of the interfacial forces, the experimental work on flow instabilities and the modelling of the interfacial area

  9. Mixed convection in a two-phase flow cooling loop

    Energy Technology Data Exchange (ETDEWEB)

    Janssens-Maenhout, G.; Daubner, M.; Knebel, J.U.

    2002-03-01

    This report summarizes the numerical simulations using the CFD code CFX4.1 which has additional models for subcooled flow boiling phenomena and the interfacial forces. The improved CFX4.1 code can be applied to the design of boiling induced mixed convection cooling loops in a defined parameter range. The experimental part describes the geysering experiments and the instability effects on the two-phase natural circulation flow. An experimentally validated flow pattern map in the Phase Change Number - Subcooling Number (N{sub PCh} - N{sub Sub}) diagram defines the operational range in which flow instabilities such as geysering can be expected. One important perspective of this combined experimental/numerical work, which is in the field of two-phase flow, is its application to the development of accelerator driven systems (ADS). The main objective on an ADS is its potential to transmute minor actinides and long-lived fission products, thus participating in closing the fuel cycle. The development of an ADS is an important issue within the Euratom Fifth FP on Partitioning and Transmutation. One concept of an ADS, which is investigated in more detail within the ''preliminary design study of an experimental ADS'' Project (PDS-XADS) of the Euratom Fifth FP, is the XADS lead-bismuth cooled Experimental ADS of ANSALDO. An essential feature of this concept is the natural circulation of the primary coolant within the reactor pool. The natural circulation, which is driven by the density differences between the blanket and the heat exchanger, is enhanced by the injection of the nitrogen cover gas through spargers located in a riser part just above the blanket. This so-called gas-lift pump system has not been investigated in more detail nor has this gas-lift pump system been numerically/experimentally confirmed. The knowledge gained within the SUCO Programe, i.e. the modelling of the interfacial forces, the experimental work on flow instabilities and the

  10. A containment convective loop analysis using the RELAP5-Mod 3.2

    International Nuclear Information System (INIS)

    Ventura, M.

    1996-01-01

    The present study was performed to verify the RELAP5-Mod 3.2 code capability to calculate convection phenomena of the type occurring in a convective loop. A simplified geometrical model of a reactor containment system was used. The parametric studies were made for the main variables which govern material transport in the volume junctions considered. The results obtained and that got using the same model with the CONTAIN code, were compared. The comparison is satisfactory. (author). 3 refs., 11 figs

  11. Active Control of Thermal Convection in a Rectangular Loop by Changing its Spatial Orientation

    Science.gov (United States)

    Bratsun, Dmitry A.; Krasnyakov, Ivan V.; Zyuzgin, Alexey V.

    2018-02-01

    The problem of the automatic control of the fluid flow in a rectangular convective loop heated from below is studied theoretically and experimentally. The control is performed by using a feedback subsystem which changes the convection regimes by introducing small discrete changes in the spatial orientation of the loop with respect to gravity. We focus on effects that arise when the feedback controller operates with an unavoidable time delay, which is cause by the thermal inertia of the medium. The mathematical model of the phenomenon is developed. The dynamic regimes of the convection in the thermosyphon loop under control are studied. It is shown that the proposed control method can successfully stabilize not only a no-motion state of the fluid, but also time-dependent modes of convection including the irregular fluid flow at high values of the Rayleigh number. It is shown that the excessive gain of the proportional feedback can result in oscillations in the loop orientation exciting the unsteady convection modes. The comparison of the experimental data obtained for dielectric oil and dodecane with theory is given, and their good agreement is demonstrated.

  12. Analysis of a convection loop for GFR post-LOCA decay heat removal

    International Nuclear Information System (INIS)

    Williams, W.C.; Hejzlar, P.; Saha, P.

    2004-01-01

    A computer code (LOCA-COLA) has been developed at MIT for steady state analysis of convective heat transfer loops. In this work, it is used to investigate an external convection loop for decay heat removal of a post-LOCA gas-cooled fast reactor (GFR). The major finding is that natural circulation cooling of the GFR is feasible under certain circumstances. Both helium and CO 2 cooled system components are found to operate in the mixed convection regime, the effects of which are noticeable as heat transfer enhancement or degradation. It is found that CO 2 outdoes helium under identical natural circulation conditions. Decay heat removal is found to have a quadratic dependence on pressure in the laminar flow regime and linear dependence in the turbulent flow regime. Other parametric studies have been performed as well. In conclusion, convection cooling loops are a credible means for GFR decay heat removal and LOCA-COLA is an effective tool for steady state analysis of cooling loops. (authors)

  13. Evaluation of T-111 forced-convection loop tested with lithium at 13700C

    International Nuclear Information System (INIS)

    DeVan, J.H.; Long, E.L. Jr.

    1975-04-01

    A T-111 alloy (Ta--8 percent W--2 percent Hf) forced-convection loop containing molten lithium was operated 3000 h at a maximum temperature of 1370 0 C. Flow velocities up to 6.3 m/s were used. The results obtained in this forced-convection loop are very similar to those observed in lower velocity thermal-convection loops of T-111 containing lithium. Weight changes were determined at 93 positions around the loop. The maximum dissolution rate occurred at the maximum wall temperature of the loop and was less than 1.3 μ m/year. Mass transfer of hafnium, nitrogen, and, to a lesser extent, carbon occurred from the hotter to cooler regions. Exposed surfaces in the highest temperature region were found to be depleted in hafnium to a depth of 60 μ m with no detectable change in tungsten content. There was some loss in room-temperature tensile strength for specimens exposed to lithium at 1370 0 C, attributable to depletion of hafnium and nitrogen and to attendant grain growth. (U.S.)

  14. Simulation of natural convection in a rectangular loop using finite elements

    International Nuclear Information System (INIS)

    Pepper, D.W.; Hamm, L.L.; Kehoe, A.B.

    1984-01-01

    A two-dimensional finite-element analysis of natural convection in a rectangular loop is presented. A psi-omega formulation of the Boussinesque approximation to the Navier-Stokes equation is solved by the false transient technique. Streamlines and isotherms at Ra = 10 4 are shown for three different modes of heating. The results indicate that corner effects should be considered when modeling flow patterns in thermosyphons

  15. Development of Capillary Loop Convective Polymerase Chain Reaction Platform with Real-Time Fluorescence Detection

    Directory of Open Access Journals (Sweden)

    Wen-Pin Chou

    2017-02-01

    Full Text Available Polymerase chain reaction (PCR has been one of the principal techniques of molecular biology and diagnosis for decades. Conventional PCR platforms, which work by rapidly heating and cooling the whole vessel, need complicated hardware designs, and cause energy waste and high cost. On the other hand, partial heating on the various locations of vessels to induce convective solution flows by buoyancy have been used for DNA amplification in recent years. In this research, we develop a new convective PCR platform, capillary loop convective polymerase chain reaction (clcPCR, which can generate one direction flow and make the PCR reaction more stable. The U-shaped loop capillaries with 1.6 mm inner diameter are designed as PCR reagent containers. The clcPCR platform utilizes one isothermal heater for heating the bottom of the loop capillary and a CCD device for detecting real-time amplifying fluorescence signals. The stable flow was generated in the U-shaped container and the amplification process could be finished in 25 min. Our experiments with different initial concentrations of DNA templates demonstrate that clcPCR can be applied for precise quantification. Multiple sample testing and real-time quantification will be achieved in future studies.

  16. Conceptual Design of Forced Convection Molten Salt Heat Transfer Testing Loop

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal; Piyush Sabharwall; Pattrick Calderoni; Alan K. Wertsching; S. Brandon Grover

    2010-09-01

    This report develops a proposal to design and construct a forced convection test loop. A detailed test plan will then be conducted to obtain data on heat transfer, thermodynamic, and corrosion characteristics of the molten salts and fluid-solid interaction. In particular, this report outlines an experimental research and development test plan. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project highlighted how thermophysical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report describes the options available to reach such objectives. In particular, that report outlines an experimental research and development test plan that would include following steps: •Molten Salts: The candidate molten salts for investigation will be selected. •Materials of Construction: Materials of construction for the test loop, heat exchangers, and fluid-solid corrosion tests in the test loop will also be selected. •Scaling Analysis: Scaling analysis to design the test loop will be performed. •Test Plan: A comprehensive test plan to include all the tests that are being planned in the short and long term time frame will be developed. •Design the Test Loop: The forced convection test loop will be designed including extensive mechanical design, instrument selection, data acquisition system, safety requirements, and related precautionary measures. •Fabricate the Test Loop. •Perform the Tests. •Uncertainty Analysis: As a part of the data collection, uncertainty analysis will

  17. Design of Test Loops for Forced Convection Heat Transfer Studies at Supercritical State

    Science.gov (United States)

    Balouch, Masih N.

    Worldwide research is being conducted to improve the efficiency of nuclear power plants by using supercritical water (SCW) as the working fluid. One such SCW reactor considered for future development is the CANDU-Supercritical Water Reactor (CANDU-SCWR). For safe and accurate design of the CANDU-SCWR, a detailed knowledge of forced-convection heat transfer in SCW is required. For this purpose, two supercritical fluid loops, i.e. a SCW loop and an R-134a loop are developed at Carleton University. The SCW loop is designed to operate at pressures as high as 28 MPa, temperatures up to 600 °C and mass fluxes of up to 3000 kg/m2s. The R-134a loop is designed to operate at pressures as high as 6 MPa, temperatures up to 140 °C and mass fluxes in the range of 500-6000 kg/m2s. The test loops designs allow for up to 300 kW of heating power to be imparted to the fluid. Both test loops are of the closed-loop design, where flow circulation is achieved by a centrifugal pump in the SCW loop and three parallel-connected gear pumps in the R-134a loop, respectively. The test loops are pressurized using a high-pressure nitrogen cylinder and accumulator assembly, which allows independent control of the pressure, while simultaneously dampening pump induced pressure fluctuations. Heat exchangers located upstream of the pumps control the fluid temperature in the test loops. Strategically located measuring instrumentation provides information on the flow rate, pressure and temperature in the test loops. The test loops have been designed to accommodate a variety of test-section geometries, ranging from a straight circular tube to a seven-rod bundle, achieving heat fluxes up to 2.5 MW/m2 depending on the test-section geometry. The design of both test loops allows for easy reconfiguration of the test-section orientation relative to the gravitational direction. All the test sections are of the directly-heated design, where electric current passing through the pressure retaining walls of the

  18. Potential of enhancing a natural convection loop with a thermomagnetically pumped ferrofluid

    Energy Technology Data Exchange (ETDEWEB)

    Aursand, Eskil; Gjennestad, Magnus Aa.; Lervåg, Karl Yngve, E-mail: karl.lervag@sintef.no; Lund, Halvor

    2016-11-01

    The feasibility of using a thermomagnetically pumped ferrofluid to enhance the performance of a natural convection cooling loop is investigated. First, a simplified analytical estimate for the thermomagnetic pumping action is derived, and then design rules for optimal solenoid and ferrofluid are presented. The design rules are used to set up a medium-scale (1 m, 10–1000 W) case study, which is modeled using a previously published and validated model (Aursand et al. [1]). The results show that the thermomagnetic driving force is significant compared to the natural convection driving force, and may in some cases greatly surpass it. The results also indicate that cooling performance can be increased by factors up to 4 and 2 in the single-phase and two-phase regimes, respectively, even when taking into the account the added heat from the solenoid. The performance increases can alternatively be used to obtain a reduction in heat-sink size by up to 75%. - Highlights: • We consider a thermomagnetically pumped ferrofluid for heat transfer. • The performance of the thermomagnetic pump is compared to natural convection. • The flow is simulated using a two-phase flow model. • The thermomagnetic driving force improves heat transfer significantly.

  19. Preliminary Numerical Analysis of Convective Heat Transfer Loop Using MARS Code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yongjae; Seo, Gwang Hyeok; Jeun, Gyoodong; Kim, Sung Joong [Hanyang Univ., Seoul (Korea, Republic of)

    2014-05-15

    The MARS has been developed adopting two major modules: RELAP5/MOD3 (USA) for one-dimensional (1D) two-fluid model for two-phase flows and COBRA-TF code for a three-dimensional (3D), two-fluid, and three-field model. In addition to the MARS code, TRACE (USA) is a modernized thermal-hydraulics code designed to consolidate and extend the capabilities of NRC's 3 legacy safety code: TRAC-P, TRAC-B and RELAP. CATHARE (French) is also thermal-hydraulic system analysis code for Pressurized Water Reactor (PWR) safety. There are several researches on comparing experimental data with simulation results by the MARS code. Kang et al. conducted natural convection heat transfer experiments of liquid gallium loop, and the experimental data were compared to MARS simulations. Bang et al. examined the capability of the MARS code to predict condensation heat transfer experiments with a vertical tube containing a non-condensable gas. Moreover, Lee et al. adopted MELCOR, which is one of the severe accident analysis codes, to evaluate several strategies for the severe accident mitigation. The objective of this study is to conduct the preliminary numerical analysis for the experimental loop at HYU using the MARS code, especially in order to provide relevant information on upcoming experiments for the undergraduate students. In this study, the preliminary numerical analysis for the convective heat transfer loop was carried out using the MARS Code. The major findings from the numerical simulations can be summarized as follows. In the calculations of the outlet and surface temperatures, the several limitations were suggested for the upcoming single-phase flow experiments. The comparison work for the HTCs shows validity for the prepared input model. This input could give useful information on the experiments. Furthermore, the undergraduate students in department of nuclear engineering, who are going to be taken part in the experiments, could prepare the program with the input, and will

  20. Preliminary Numerical Analysis of Convective Heat Transfer Loop Using MARS Code

    International Nuclear Information System (INIS)

    Lee, Yongjae; Seo, Gwang Hyeok; Jeun, Gyoodong; Kim, Sung Joong

    2014-01-01

    The MARS has been developed adopting two major modules: RELAP5/MOD3 (USA) for one-dimensional (1D) two-fluid model for two-phase flows and COBRA-TF code for a three-dimensional (3D), two-fluid, and three-field model. In addition to the MARS code, TRACE (USA) is a modernized thermal-hydraulics code designed to consolidate and extend the capabilities of NRC's 3 legacy safety code: TRAC-P, TRAC-B and RELAP. CATHARE (French) is also thermal-hydraulic system analysis code for Pressurized Water Reactor (PWR) safety. There are several researches on comparing experimental data with simulation results by the MARS code. Kang et al. conducted natural convection heat transfer experiments of liquid gallium loop, and the experimental data were compared to MARS simulations. Bang et al. examined the capability of the MARS code to predict condensation heat transfer experiments with a vertical tube containing a non-condensable gas. Moreover, Lee et al. adopted MELCOR, which is one of the severe accident analysis codes, to evaluate several strategies for the severe accident mitigation. The objective of this study is to conduct the preliminary numerical analysis for the experimental loop at HYU using the MARS code, especially in order to provide relevant information on upcoming experiments for the undergraduate students. In this study, the preliminary numerical analysis for the convective heat transfer loop was carried out using the MARS Code. The major findings from the numerical simulations can be summarized as follows. In the calculations of the outlet and surface temperatures, the several limitations were suggested for the upcoming single-phase flow experiments. The comparison work for the HTCs shows validity for the prepared input model. This input could give useful information on the experiments. Furthermore, the undergraduate students in department of nuclear engineering, who are going to be taken part in the experiments, could prepare the program with the input, and will

  1. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

    International Nuclear Information System (INIS)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for single-phase natural convection in an experimental sodium loop. The tests were conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) Facility, an engineering-scale high temperature sodium facility at the Oak Ridge National Laboratory used for thermal-hydraulic testing of simulated LMFBR subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during these tests was typical of decay heat levels. Tests were conducted both with zero initial forced flow and with a small initial forced flow. The bypass line was closed in most tests, but open in one. The computer code used to analyze these tests [LONAC (LOw flow and NAtural Convection)] is an ORNL-developed, fast running, one-dimensional, single-phase finite difference model for simulating forced and free convection transients in the THORS loop

  2. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop.

  3. Comparison of numerical results with experimental data for single-phase natural convection in an experimental sodium loop

    International Nuclear Information System (INIS)

    Ribando, R.J.

    1979-01-01

    A comparison is made between computed results and experimental data for a single-phase natural convection test in an experimental sodium loop. The test was conducted in the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility, an engineering-scale high temperature sodium loop at the Oak Ridge National Laboratory (ORNL) used for thermal-hydraulic testing of simulated Liquid Metal Fast Breeder Reactor (LMFBR) subassemblies at normal and off-normal operating conditions. Heat generation in the 19 pin assembly during the test was typical of decay heat levels. The test chosen for analysis in this paper was one of seven natural convection runs conducted in the facility using a variety of initial conditions and testing parameters. Specifically, in this test the bypass line was open to simulate a parallel heated assembly and the test was begun with a pump coastdown from a small initial forced flow. The computer program used to analyze the test, LONAC (LOw flow and NAtural Convection) is an ORNL-developed, fast-running, one-dimensional, single-phase, finite-difference model used for simulating forced and free convection transients in the THORS loop

  4. Experimental analysis of the natural convection system through a closed loop under transient regime

    International Nuclear Information System (INIS)

    Lavrador, Marcelo de Bastos; Braga, Carlos Valois Maciel; Carajilescov, Pedro

    1996-01-01

    This work presents the experimental model used in the study of closed loop natural convection (thermosyphons). Details of the main circuit and information on the used instrumentation are also presented. The study aimed the circuit thermal performance, initially justifying the oscillatory behaviour of the time vs. temperature curves. As expected, the curves for the cold leg presented an oscillation amplitude lesser than those for hot leg since the 'peaks' which reveal high temperature spots disappear due to the heat transfer to the cooling water. Those curves were not influenced within the measured range, by the changes occurred in the cooling water flow (secondary circuit). Besides, when varying the power supplied by the hot source it was observed a variation directly proportional of the oscillation frequency, of the oscillation amplitude, and the difference between the hot and cold legs temperatures. Concerning to the forced power variations, it is observed that the oscillation is always restarted and the final results are related to the second applied power

  5. Application of a bistable convection loop to LMFBR [liquid metal fast breeder reactor] emergency core cooling

    International Nuclear Information System (INIS)

    Anand, G.; Christensen, R.N.

    1990-01-01

    The concept of passive safety features for nuclear reactors has been developed in recent years and has gained wide acceptance. A literature survey of current reactors with passive features indicates that these reactors have some passive features but still do not fully meet the design objectives. Consider a current liquid-metal reactor design like PRISM. During normal operation, liquid sodium enters the reactor at ∼395 degree C and exits at ∼550 degree C. In the event of loss of secondary cooling with or without scram, the primary coolant (liquid sodium) initially acts as a heat sink and its temperature increases. For events without scram, the negative reactivity induced by the increase in temperature shuts the reactor down. When the average temperature of the sodium reaches ∼600 to 650 degree C, it overflows from the reactor vessel, activating the auxiliary cooling system. The auxiliary cooling system uses natural circulation of air around the reactor guard vessel. An alternative to the current design incorporates a bistable convection loop (BCL). The incorporation of the BCL concept remarkably improves the safety of the nuclear reactors. Application of the BCL concept to liquid-metal fast breeder reactors is described in this paper

  6. Design and operation of thermal-convection loops for corrosion measurements in LiF--LiCl--LiBr

    International Nuclear Information System (INIS)

    Keiser, J.R.; DeVan, J.H.

    1979-01-01

    Using a most sophisticated design of a thermal-convection loop to study the corrosion behavior of type 316 stainless steel and the salt mixture LiF--LiCl--LiBr is reported. The corrosion rate is being determined as a function of time and temperature through weight change measurements. The maximum corrosion rate measured is about 20 μm/year on removable corrosion specimens. Controlled potential voltammetry has been found to be satisfactory and is being used to monitor the oxidation potential of the salt. Measurements demonstrate the effect on the oxidation potential of impurities introduced during specimen insertion, and techniques should show the effect of a lithium addition on the oxidation potential

  7. Post shut-down decay heat removal from nuclear reactor core by natural convection loops in sodium pool

    Energy Technology Data Exchange (ETDEWEB)

    Rajamani, A. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Sundararajan, T., E-mail: tsundar@iitm.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Prasad, B.V.S.S.S. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Parthasarathy, U.; Velusamy, K. [Nuclear Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2016-05-15

    Highlights: • Transient simulations are performed for a worst case scenario of station black-out. • Inter-wrapper flow between various sub-assemblies reduces peak core temperature. • Various natural convection paths limits fuel clad temperatures below critical level. - Abstract: The 500 MWe Indian pool type Prototype Fast Breeder Reactor (PFBR) has a passive core cooling system, known as the Safety Grade Decay Heat Removal System (SGDHRS) which aids to remove decay heat after shut down phase. Immediately after reactor shut down the fission products in the core continue to generate heat due to beta decay which exponentially decreases with time. In the event of a complete station blackout, the coolant pump system may not be available and the safety grade decay heat removal system transports the decay heat from the core and dissipates it safely to the atmosphere. Apart from SGDHRS, various natural convection loops in the sodium pool carry the heat away from the core and deposit it temporarily in the sodium pool. The buoyancy driven flow through the small inter-wrapper gaps (known as inter-wrapper flow) between fuel subassemblies plays an important role in carrying the decay heat from the sub-assemblies to the hot sodium pool, immediately after reactor shut down. This paper presents the transient prediction of flow and temperature evolution in the reactor subassemblies and the sodium pool, coupled with the safety grade decay heat removal system. It is shown that with a properly sized decay heat exchanger based on liquid sodium and air chimney stacks, the post shutdown decay heat can be safely dissipated to atmospheric air passively.

  8. Natural convection liquid desiccant loop as an auxiliary air conditioning system: investigating the operational parameters

    Science.gov (United States)

    Fazilati, Mohammad Ali; Alemrajabi, Ali Akbar; Sedaghat, Ahmad

    2018-03-01

    Liquid desiccant air conditioning system with natural convection was presented previously as a new generation of AC systems. The system consists of two three-fluid energy exchangers namely absorber and regenerator in which the action of air dehumidifying and desiccant regeneration is done, respectively. The influence of working parameters on system performance including the heat source and heat sink temperature, concentration of desiccant solution fills the system initially and humidity content of inlet air to regenerator is investigated experimentally. The heat source temperatures of 50 °C and 60 °C, heat sink temperatures of 15 °C and 20 °C and desiccant concentrations of 30% and 34%, are examined here. The inlet air to regenerator has temperature of 38.5 °C and three relative humidity of 14%, 38% and 44%. In all experiments, the inlet air to absorber has temperature of 31 °C and relative humidity of 75%. By inspecting evaluation indexes of system, it is revealed that higher startup desiccant concentration solution is more beneficial for all study cases. It is also observed although the highest/lowest temperature heat source/heat sink is most suitable for best system operation, increasing the heat source temperature should be accompanied with decreasing heat sink temperature. Using drier air stream for regenerator inlet does not necessarily improve system performance; and the air stream with proper value of humidity content should be employed. Finally after running the system in its best working condition, the coefficient of performance (COP) reached 4.66 which verified to be higher than when the same air conditioning task done by a conventional vapor compression system, in which case the COP was 3.38.

  9. Benchmarking of thermalhydraulic loop models for lead-alloy-cooled advanced nuclear energy systems. Phase I: Isothermal forced convection case

    International Nuclear Information System (INIS)

    2012-06-01

    Under the auspices of the NEA Nuclear Science Committee (NSC), the Working Party on Scientific Issues of the Fuel Cycle (WPFC) has been established to co-ordinate scientific activities regarding various existing and advanced nuclear fuel cycles, including advanced reactor systems, associated chemistry and flowsheets, development and performance of fuel and materials and accelerators and spallation targets. The WPFC has different expert groups to cover a wide range of scientific issues in the field of nuclear fuel cycle. The Task Force on Lead-Alloy-Cooled Advanced Nuclear Energy Systems (LACANES) was created in 2006 to study thermal-hydraulic characteristics of heavy liquid metal coolant loop. The objectives of the task force are to (1) validate thermal-hydraulic loop models for application to LACANES design analysis in participating organisations, by benchmarking with a set of well-characterised lead-alloy coolant loop test data, (2) establish guidelines for quantifying thermal-hydraulic modelling parameters related to friction and heat transfer by lead-alloy coolant and (3) identify specific issues, either in modelling and/or in loop testing, which need to be addressed via possible future work. Nine participants from seven different institutes participated in the first phase of the benchmark. This report provides details of the benchmark specifications, method and code characteristics and results of the preliminary study: pressure loss coefficient and Phase-I. A comparison and analysis of the results will be performed together with Phase-II

  10. Single and two-phase similarity analysis of a reduced-scale natural convection loop relative to a full-scale prototype

    International Nuclear Information System (INIS)

    Botelho, David A.; Faccini, Jose L.H.

    2002-01-01

    The main topic in this paper is a new device being considered to improve nuclear reactor safety employing the natural circulation. A scaled experiment used to demonstrate the performance of the device is also described. We also applied a similarity analysis method for single and two-phase natural convection loop flow to the IEN CCN experiment and to an APEX like experiment to verify the degree of similarity relative to a full-scale prototype like the AP600. Most of the CCN similarity numbers that represent important single and two-phase similarity conditions are comparable to the APEX like loop non-dimensional numbers calculated employing the same methodology. Despite the much smaller geometric, pressure, and power scales, we conclude that the IEN CCN has single and two-phase natural circulation similarity numbers that represent fairly well the full-scale prototype. even lacking most complementary primary and safety systems, this IEN circuit provided a much valid experience to develop human, experimental, and analytical resources, besides its utilization as a training tool. (author)

  11. Experimental and numerical thermohydraulic study of a supercritical helium loop in forced convection under pulsed heat loads

    International Nuclear Information System (INIS)

    Lagier, Benjamin

    2014-01-01

    Future fusion reactor devices such as ITER or JT-60SA will produce thermonuclear fusion reaction in plasmas at several millions of degrees. The confinement in the center of the chamber is achieved by very intense magnetic fields generated by superconducting magnets. These coils have to be cooled down to 4.4 K through a forced flow of supercritical helium. The cyclic behavior of the machines leads to pulsed thermal heat loads which will have to be handled by the refrigerator. The HELIOS experiment built in CEA Grenoble is a scaled down model of the helium distribution system of the tokamak JT-60SA composed of a saturated helium bath and a supercritical helium loop. The thesis work explores HELIOS capabilities for experimental and numerical investigations on three heat load smoothing strategies: the use of the saturated helium bath as an open thermal buffer, the rotation speed variation of the cold circulator and the bypassing of the heated section. The developed model describes well the physical evolutions of the helium loop (pressure, temperature, mass flow) submitted to heat loads observed during experiments. Advanced controls have been tested and validated to improve the stability of the refrigerator and to optimize the refrigeration power. (author) [fr

  12. Thermal convection loop experiments and analysis of mass transport process in Lithium/Fe-12Cr-1MoVW systems

    International Nuclear Information System (INIS)

    Bell, G.E.C.

    1988-01-01

    Lithium is an attractive coolant and breeder material for first- generation fusion reactor blankets. The compatibility of lithium with structural alloys, in the form of mass transport and deposition, may impose restrictions on blanket operating parameters such as temperature and lithium purity. A ferritic steel, such as Fe-12CrlMoVW, is a candidate for use as a structural alloy in a self-cooled lithium blanket design. Experimental data on mass transport in lithium/Fe-12CrlMoVW were obtained from two thermal convection loops which spanned the fusion relevant temperature range; one operated from 360 to 505/degree/C for 3040 hours and the other from 525 to 655/degree/C for 2510 hours. The experimental effort was supported by analysis of the mechanisms and processes of mass transport and deposition. It was found that mass transport and deposition, as measured by specimen weight change, were not simple functions of temperature for the entire temperature range investigated. The mass transfer behavior and surface morphology at low temperatures were dominated by impurity reactions of nitrogen and carbon in the lithium with the steel. In the experiment between 360 and 505/degree/C, nitrogen levels were sufficient below 450/degree/C to allow the formation of the adherent, protective corrosion product Li 9 CrN 5 . Weight losses in the 360 to 505/degree/C experiment were insensitive to temperature below 450/degree/C. Between 450 and 505/degree/C, the precipitation of carbon in the form of chromium-rich M 23 C 6 (M = Fe or Cr) carbides, due to the formation of Li 9 CrN 5 and corresponding release of carbon, resulted in weight gains for the highest temperature specimens in the experiment. 98 refs., 83 figs., 9 tabs

  13. Active control of convection

    Energy Technology Data Exchange (ETDEWEB)

    Bau, H.H. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  14. System design description of forced-convection molten-salt corrosion loops MSR-FCL-3 and MSR-FCL-4

    International Nuclear Information System (INIS)

    Huntley, W.R.; Silverman, M.D.

    1976-11-01

    Molten-salt corrosion loops MSR-FCL-3 and MSR-FCL-4 are high-temperature test facilities designed to evaluate corrosion and mass transfer of modified Hastelloy N alloys for future use in Molten-Salt Breeder Reactors. Salt is circulated by a centrifugal sump pump to evaluate material compatibility with LiF-BeF 2 -ThF 4 -UF 4 fuel salt at velocities up to 6 m/s (20 fps) and at salt temperatures from 566 to 705 0 C (1050 to 1300 0 F). The report presents the design description of the various components and systems that make up each corrosion facility, such as the salt pump, corrosion specimens, salt piping, main heaters, salt coolers, salt sampling equipment, and helium cover-gas system, etc. The electrical systems and instrumentation and controls are described, and operational procedures, system limitations, and maintenance philosophy are discussed

  15. Heat transfer measurements in a forced convection loop with two molten-fluoride salts: LiF--BeF2--ThF2--UF4 and eutectic NaBF4--NaF

    International Nuclear Information System (INIS)

    Silverman, M.D.; Huntley, W.R.; Robertson, H.E.

    1976-10-01

    Heat transfer coefficients were determined experimentally for two molten-fluoride salts [LiF-BeF 2 -ThF 2 -UF 4 (72-16-12-0.3 mole %) and NaBF 4 -NaF (92-8 mole %] proposed as the fuel salt and coolant salt, respectively, for molten-salt breeder reactors. Information was obtained over a wide range of variables, with salt flowing through 12.7-mm-OD (0.5-in.) Hastelloy N tubing in a forced convection loop (FCL-2b). Satisfactory agreement with the empirical Sieder-Tate correlation was obtained in the fully developed turbulent region at Reynolds moduli above 15,000 and with a modified Hausen equation in the extended transition region (Re approx.2100-15,000). Insufficient data were obtained in the laminar region to allow any conclusions to be drawn. These results indicate that the proposed salts behave as normal heat transfer fluids with an extended transition region

  16. Loop kinematics

    International Nuclear Information System (INIS)

    Migdal, A.A.

    1982-01-01

    Basic operators acting in the loop space are introduced. The topology of this space and properties of the Stokes type loop functionals are discussed. The parametrically invariant loop calculus developed here is used in the loop dynamics

  17. Boiling induced mixed convection in cooling loops

    International Nuclear Information System (INIS)

    Knebel, J.U.; Janssens-Maenhout, G.; Mueller, U.

    2000-01-01

    This article describes the SUCO program performed at the Forschungszentrum Karlsruhe. The SUCO program is a three-step series of scaled model experiments investigating the possibility of a sump cooling concept for future light water reactors. In case of a core melt accident, the sump cooling concept realises a decay heat removal system that is based on passive safety features within the containment. The article gives, first, results of the experiments in the 1:20 linearly scaled SUCOS-2D test facility. The experimental results are scaled-up to the conditions in the prototype, allowing a statement with regard to the feasibility of the sump cooling concept. Second, the real height SUCOT test facility with a volume and power scale of 1:356 that is aimed at investigating the mixed single-phase and two-phase natural circulation flow in the reactor sump, together with first measurement results, are discussed. Finally, a numerical approach to model the subcooled nucleate boiling phenomena in the test facility SUCOT is presented. Physical models describing interfacial mass, momentum and-heat transfer are developed and implemented in the commercial software package CFX4.1. The models are validated for an isothermal air-water bubbly flow experiment and a subcooled boiling experiment in vertical annular water flow. (author)

  18. Heat Convection

    Science.gov (United States)

    Jiji, Latif M.

    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the follow ing ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters.

  19. National Convective Weather Diagnostic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current convective hazards identified by the National Convective Weather Detection algorithm. The National Convective Weather Diagnostic (NCWD) is an automatically...

  20. Energy house - dream house

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    An energy house a prefabricated house with an extensive minimization of heat losses, is air-conditioned by means of a combined heating system consisting of hot water cycle and recirculating heating. The energy system is trivalent: wind power, solar energy with heat pumps and normal oil heating.

  1. Convective heat flow probe

    Science.gov (United States)

    Dunn, James C.; Hardee, Harry C.; Striker, Richard P.

    1985-01-01

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packer-type seals are provided along the probe above and below the heater pads.

  2. Magnetic Fields in the Solar Convection Zone

    Directory of Open Access Journals (Sweden)

    Fan Yuhong

    2004-07-01

    Full Text Available Recent studies of the dynamic evolution of magnetic flux tubes in the solar convection zone are reviewed with focus on emerging flux tubes responsible for the formation of solar active regions. The current prevailing picture is that active regions on the solar surface originate from strong toroidal magnetic fields generated by the solar dynamo mechanism at the thin tachocline layer at the base of the solar convection zone. Thus the magnetic fields need to traverse the entire convection zone before they reach the photosphere to form the observed solar active regions. This review discusses results with regard to the following major topics: 1. the equilibrium properties of the toroidal magnetic fields stored in the stable overshoot region at the base of the convection zone, 2. the buoyancy instability associated with the toroidal magnetic fields and the formation of buoyant magnetic flux tubes, 3. the rise of emerging flux loops through the solar convective envelope as modeled by the thin flux tube calculations which infer that the field strength of the toroidal magnetic fields at the base of the solar convection zone is significantly higher than the value in equipartition with convection, 4. the minimum twist needed for maintaining cohesion of the rising flux tubes, 5. the rise of highly twisted kink unstable flux tubes as a possible origin of d -sunspots, 6. the evolution of buoyant magnetic flux tubes in 3D stratified convection, 7. turbulent pumping of magnetic flux by penetrative compressible convection, 8. an alternative mechanism for intensifying toroidal magnetic fields to significantly super-equipartition field strengths by conversion of the potential energy associated with the superadiabatic stratification of the solar convection zone, and finally 9. a brief overview of our current understanding of flux emergence at the surface and post-emergence evolution of the subsurface magnetic fields.

  3. Autonomous houses. Autonomous house

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, S. (Tokai University, Tokyo (Japan). Faculty of Engineering)

    1991-09-30

    Self-sufficiency type houses are outlined. On condition that people gain a certain amount of income in relation with the society, they self-suffice under the given environment, allowing themselves to accept a minimum of industrial products with small environmental load. Ordinary supply from outside of fossil energy and materials which depend on it is minimized. Types are classified into three: energy, energy materials and perfect self-sufficiency. A study project for environment symbiotic houses is progressing which is planned by the Ministry of Construction and Institute of Building Energy Conservation and is invested by a private company. Its target is making a house for halving an environmental load by CO{sub 2}, for the purpose of creating the environment symbiotic house which is nice to and in harmony with the global environment and human beings. As a part of the studies on energy-saving and resource conservation on houses, introduced is a plan of an autonomous house at Izu-Atagawa. The passive method and high thermal-insulation are used for air conditioning, and hot spring water for hot water supply. Electric power is generated by hydroelectric power generation using mountain streams and by solar cells. Staple food is purchased, while subsidiary food is sufficed. 17 refs., 4 figs., 1 tab.

  4. National Convective Weather Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NCWF is an automatically generated depiction of: (1) current convection and (2) extrapolated signficant current convection. It is a supplement to, but does NOT...

  5. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Andreasen, Casper Schousboe; Aage, Niels

    stabilised finite elements implemented in a parallel multiphysics analysis and optimisation framework DFEM [1], developed and maintained in house. Focus is put on control of the temperature field within the solid structure and the problems can therefore be seen as conjugate heat transfer problems, where heat...... conduction governs in the solid parts of the design domain and couples to convection-dominated heat transfer to a surrounding fluid. Both loosely coupled and tightly coupled problems are considered. The loosely coupled problems are convection-diffusion problems, based on an advective velocity field from...

  6. Housing culture

    DEFF Research Database (Denmark)

    Roesdahl, Else; Scholkmann, Barbara

    2007-01-01

    On houses and their furniture and fittings, and on the study of this - with a comparison of rural, urban, monastic and aristocratic housing, and a special section on heating technologies.......On houses and their furniture and fittings, and on the study of this - with a comparison of rural, urban, monastic and aristocratic housing, and a special section on heating technologies....

  7. Natural Convection Analysis with Various Turbulent Models Using FLUENT

    International Nuclear Information System (INIS)

    Park, Yu Sun

    2007-01-01

    The buoyancy driven convective flow fields are steady circulatory flows which were made between surfaces maintained at two fixed temperatures. They are ubiquitous in nature and play an important role in many engineering applications. Especially, in last decades, natural convection in a close loop or cavity becomes the main issue in the molecular biology for the polymerase chain reaction (PCR). Application of a natural convection can reduce the costs and efforts remarkably. This paper focuses on the sensitivity study of turbulence analysis using CFD for a natural convection in a closed rectangular cavity. Using commercial CFD code, FLUENT, various turbulent models were applied to the turbulent flow. Results from each CFD model will be compared each other in the viewpoints of flow characteristics. This work will suggest the best turbulent model of CFD for analyzing turbulent flows of the natural convection in an enclosure system

  8. Thermo-mechanical behaviour of FBTR reactor vessel due to natural convection in cover gas space

    International Nuclear Information System (INIS)

    Srinivasan, G.; Varadarajan, S.; Kapoor, R.P.

    1988-01-01

    Fast Breeder Test Reactor is a 40 MW(t), loop type sodium cooled reactor, similar in design to Rapsodie. The Reactor Assembly, which is the heart of FBTR, comprises the Reactor Vessel (RV) housed in a safety vessel within a concrete cell (A1 Cell). The RV which supports the core is shielded at the top by two rotatable plugs which are stacked with layers of borated graphite and steel. The smaller plug (SRP), is mounted excentric to the larger one (LRP). A nominal annular gap of 16 mm is provided between RV and LRP and between LRP and SRP to enable free rotation of the plugs. Stainless Steel insulation is fixed inside the steel vessel, to avoid overheating of the A1 Cell concrete. The core is supported by the Grid Plate (GP), bolted to the RV. During preheating, sodium charging and isothermal runs upto 350 0 C, temperature asymmetries were noticed in the reactor vessel wall in the cover gas space. This was attributable to convection currents in the annulus between RV and LRP. The asymmetries also resulted in a lateral shift of the grid plate. This paper discusses our experience in suppressing these convection currents, and minimising the grid plate shift

  9. PONDEROMOTIVE ACCELERATION IN CORONAL LOOPS

    Energy Technology Data Exchange (ETDEWEB)

    Dahlburg, R. B.; Obenschain, K. [LCP and FD, Naval Research Laboratory, Washington, DC 20375 (United States); Laming, J. M. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Taylor, B. D. [AFRL Eglin AFB, Pensacola, FL 32542 (United States)

    2016-11-10

    Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3–4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

  10. PONDEROMOTIVE ACCELERATION IN CORONAL LOOPS

    International Nuclear Information System (INIS)

    Dahlburg, R. B.; Obenschain, K.; Laming, J. M.; Taylor, B. D.

    2016-01-01

    Ponderomotive acceleration has been asserted to be a cause of the first ionization potential (FIP) effect, the well-known enhancement in abundance by a factor of 3–4 over photospheric values of elements in the solar corona with FIP less than about 10 eV. It is shown here by means of numerical simulations that ponderomotive acceleration occurs in solar coronal loops, with the appropriate magnitude and direction, as a “by-product” of coronal heating. The numerical simulations are performed with the HYPERION code, which solves the fully compressible three-dimensional magnetohydrodynamic equations including nonlinear thermal conduction and optically thin radiation. Numerical simulations of coronal loops with an axial magnetic field from 0.005 to 0.02 T and lengths from 25,000 to 75,000 km are presented. In the simulations the footpoints of the axial loop magnetic field are convected by random, large-scale motions. There is a continuous formation and dissipation of field-aligned current sheets, which act to heat the loop. As a consequence of coronal magnetic reconnection, small-scale, high-speed jets form. The familiar vortex quadrupoles form at reconnection sites. Between the magnetic footpoints and the corona the reconnection flow merges with the boundary flow. It is in this region that the ponderomotive acceleration occurs. Mirroring the character of the coronal reconnection, the ponderomotive acceleration is also found to be intermittent.

  11. Mathematical Modeling of Loop Heat Pipes

    Science.gov (United States)

    Kaya, Tarik; Ku, Jentung; Hoang, Triem T.; Cheung, Mark L.

    1998-01-01

    The primary focus of this study is to model steady-state performance of a Loop Heat Pipe (LHP). The mathematical model is based on the steady-state energy balance equations at each component of the LHP. The heat exchange between each LHP component and the surrounding is taken into account. Both convection and radiation environments are modeled. The loop operating temperature is calculated as a function of the applied power at a given loop condition. Experimental validation of the model is attempted by using two different LHP designs. The mathematical model is tested at different sink temperatures and at different elevations of the loop. Tbc comparison of the calculations and experimental results showed very good agreement (within 3%). This method proved to be a useful tool in studying steady-state LHP performance characteristics.

  12. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-11-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  13. Corrosion in lithium-stainless steel thermal-convection systems

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.; Selle, J.E.

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650 0 C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop

  14. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  15. Clay Houses

    Science.gov (United States)

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  16. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  17. Tech House

    Science.gov (United States)

    1978-01-01

    The members of the Swain family- Dr. Charles "Bill" Swain, wife Elaine, daughter Carol, 17, son "Chuck", 12, and dog Susie have an interesting assignment. They are active participants in an important NASA research program involving the application of space-age technology to home construction. b' Transplanted Floridians, the Swains now reside in NASA's Tech House, loatedat Langley Research Center, Hampton, Virginia. Their job is to use and help evaluate the variety of advanced technology systems in Tech House. A contemporary three-bedroom home, Tech House incorporates NASA technology, the latest commercial building techniques and other innovations, all designed to reduce energy and water consumption and to provide new levels of comfort, convenience, security and fire safety. Tech House equipment performed well in initial tests, but a house is not a home until it has people. That's where the Swains come in. NASA wants to see how the various systems work under actual living conditions, to confirm the effectiveness of the innovations or to determine necessary modifications for improvement. The Swains are occupying the house for a year, during which NASA engineers are computer monitoring the equipment and assembling a record of day-to-day performance. . Tech House is a laboratory rather than a mass production prototype, but its many benefits may influence home design and construction. In a period of sharply rising utility costs, widespread adoption of Tech House features could provide large-scale savings to homeowners and potentially enormous national benefit in resources conservation. Most innovations are aerospace spinoffs: Some of the equipment is now commercially available; other systems are expected to be in production within a few years. Around 1980, a Tech House-type of home could be built for $45-50,000 (1 976 dollars). It is estimated that the homeowner would save well over $20,000 (again 1976 dollars) in utility costs over the average mortgage span of 20 years.

  18. CDBG Housing Activity

    Data.gov (United States)

    Department of Housing and Urban Development — CDBG activity related to housing, including multifamily rehab, housing services, code enforcement, operation and repair of foreclosed property and public housing...

  19. Simulating deep convection with a shallow convection scheme

    Directory of Open Access Journals (Sweden)

    C. Hohenegger

    2011-10-01

    Full Text Available Convective processes profoundly affect the global water and energy balance of our planet but remain a challenge for global climate modeling. Here we develop and investigate the suitability of a unified convection scheme, capable of handling both shallow and deep convection, to simulate cases of tropical oceanic convection, mid-latitude continental convection, and maritime shallow convection. To that aim, we employ large-eddy simulations (LES as a benchmark to test and refine a unified convection scheme implemented in the Single-column Community Atmosphere Model (SCAM. Our approach is motivated by previous cloud-resolving modeling studies, which have documented the gradual transition between shallow and deep convection and its possible importance for the simulated precipitation diurnal cycle.

    Analysis of the LES reveals that differences between shallow and deep convection, regarding cloud-base properties as well as entrainment/detrainment rates, can be related to the evaporation of precipitation. Parameterizing such effects and accordingly modifying the University of Washington shallow convection scheme, it is found that the new unified scheme can represent both shallow and deep convection as well as tropical and mid-latitude continental convection. Compared to the default SCAM version, the new scheme especially improves relative humidity, cloud cover and mass flux profiles. The new unified scheme also removes the well-known too early onset and peak of convective precipitation over mid-latitude continental areas.

  20. White House

    Science.gov (United States)

    ... content Jump to navigation the WHITE HOUSE President Donald J. Trump Get in Touch Home Briefing Room From the ... For All Americans The Administration The Administration President Donald J. Trump Vice President Mike Pence First Lady Melania Trump ...

  1. Conformal house

    DEFF Research Database (Denmark)

    Ryttov, Thomas Aaby; Sannino, Francesco

    2010-01-01

    fixed point. As a consistency check we recover the previously investigated bounds of the conformal windows when restricting to a single matter representation. The earlier conformal windows can be imagined to be part now of the new conformal house. We predict the nonperturbative anomalous dimensions...... at the infrared fixed points. We further investigate the effects of adding mass terms to the condensates on the conformal house chiral dynamics and construct the simplest instanton induced effective Lagrangian terms...

  2. Convection and stellar oscillations

    DEFF Research Database (Denmark)

    Aarslev, Magnus Johan

    2017-01-01

    for asteroseismology, because of the challenges inherent in modelling turbulent convection in 1D stellar models. As a result of oversimplifying the physics near the surface, theoretical calculations systematically overestimate the oscillation frequencies. This has become known as the asteroseismic surface effect. Due...... to lacking better options, this frequency difference is typically corrected for with ad-hoc formulae. The topic of this thesis is the improvement of 1D stellar convection models and the effects this has on asteroseismic properties. The source of improvements is 3D simulations of radiation...... atmospheres to replace the outer layers of stellar models. The additional turbulent pressure and asymmetrical opacity effects in the atmosphere model, compared to convection in stellar evolution models, serve to expand the atmosphere. The enlarged acoustic cavity lowers the pulsation frequencies bringing them...

  3. Liquid Lead-Bismuth Materials Test Loop

    International Nuclear Information System (INIS)

    Tcharnotskaia, Valentina; Ammerman, Curtt; Darling, Timothy; King, Joe; Li, Ning; Shaw, Don; Snodgrass, Leon; Woloshun, Keith

    2002-01-01

    We designed and built the Liquid Lead-Bismuth Materials Test Loop (MTL) to study the materials behavior in a flow of molten lead-bismuth eutectic (LBE). In this paper we present a description of the loop with main components and their functions. Stress distribution in the piping due to sustained, occasional and expansion loads is shown. The loop is designed so that a difference of 100 deg. C can be attained between the coldest and the hottest parts at a nominal flow rate of 8.84 GPM. Liquid LBE flow can be activated by a mechanical sump pump or by natural convection. In order to maintain a self-healing protective film on the surface of the stainless steel pipe, a certain concentration of oxygen has to be maintained in the liquid metal. We developed oxygen sensors and an oxygen control system to be implemented in the loop. The loop is outfitted with a variety of instruments that are controlled from a computer based data acquisition system. Initial experiments include preconditioning the loop, filling it up with LBE, running at uniform temperature and tuning the oxygen control system. We will present some preliminary results and discuss plans for the future tests. (authors)

  4. Convective transport in tokamaks

    International Nuclear Information System (INIS)

    D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.; Krasheninnikov, S.I.; Pigarov, A.Yu.; Yu, G.Q.; Xu, X.Q.; Nevins, W.M.

    2005-01-01

    Scrape-off-layer (SOL) convection in fusion experiments appears to be a universal phenomenon that can 'short-circuit' the divertor in some cases. The theory of 'blob' transport provides a simple and robust physical paradigm for studying convective transport. This paper summarizes recent advances in the theory of blob transport and its comparison with 2D and 3D computer simulations. We also discuss the common physical basis relating radial transport of blobs, pellets, and ELMs and a new blob regime that may lead to a connection between blob transport and the density limit. (author)

  5. Physics of Stellar Convection

    Science.gov (United States)

    Arnett, W. David

    2009-05-01

    We review recent progress using numerical simulations as a testbed for development of a theory of stellar convection, much as envisaged by John von Newmann. Necessary features of the theory, non-locality and fluctuations, are illustrated by computer movies. It is found that the common approximation of convection as a diffusive process presents the wrong physical picture, and improvements are suggested. New observational results discussed at the conference are gratifying in their validation of some of our theoretical ideas, especially the idea that SNIb and SNIc events are related to the explosion of massive star cores which have been stripped by mass loss and binary interactions [1

  6. Parameterizing convective organization

    Directory of Open Access Journals (Sweden)

    Brian Earle Mapes

    2011-06-01

    Full Text Available Lateral mixing parameters in buoyancy-driven deep convection schemes are among the most sensitive and important unknowns in atmosphere models. Unfortunately, there is not a true optimum value for plume mixing rate, but rather a dilemma or tradeoff: Excessive dilution of updrafts leads to unstable stratification bias in the mean state, while inadequate dilution allows deep convection to occur too easily, causing poor space and time distributions and variability. In this too-small parameter space, compromises are made based on competing metrics of model performance. We attempt to escape this “entrainment dilemma” by making bulk plume parameters (chiefly entrainment rate depend on a new prognostic variable (“organization,” org meant to reflect the rectified effects of subgrid-scale structure in meteorological fields. We test an org scheme in the Community Atmosphere Model (CAM5 with a new unified shallow-deep convection scheme (UW-ens, a 2-plume version of the University of Washington scheme. Since buoyant ascent involves natural selection, subgrid structure makes convection systematically deeper and stronger than the pure unorganized case: plumes of average (or randomly sampled air rising in the average environment. To reflect this, org is nonnegative, but we leave it dimensionless. A time scale characterizes its behavior (here ∼3 h for a 2o model. Currently its source is rain evaporation, but other sources can be added easily. We also let org be horizontally transported by advection, as a mass-weighted mean over the convecting layer. Linear coefficients link org to a plume ensemble, which it assists via: 1 plume base warmth above the mean temperature 2 plume radius enhancement (reduced mixing, and 3 increased probability of overlap in a multi-plume scheme, where interactions benefit later generations (this part has only been implemented in an offline toy column model. Since rain evaporation is a source for org, it functions as a time

  7. Mathematical models of convection

    CERN Document Server

    Andreev, Victor K; Goncharova, Olga N; Pukhnachev, Vladislav V

    2012-01-01

    Phenomena of convection are abundant in nature as well as in industry. This volume addresses the subject of convection from the point of view of both, theory and application. While the first three chapters provide a refresher on fluid dynamics and heat transfer theory, the rest of the book describes the modern developments in theory. Thus it brings the reader to the ""front"" of the modern research. This monograph provides the theoretical foundation on a topic relevant to metallurgy, ecology, meteorology, geo-and astrophysics, aerospace industry, chemistry, crystal physics, and many other fiel

  8. Convective aggregation in realistic convective-scale simulations

    OpenAIRE

    Holloway, Christopher E.

    2017-01-01

    To investigate the real-world relevance of idealized-model convective self-aggregation, five 15-day cases of real organized convection in the tropics are simulated. These include multiple simulations of each case to test sensitivities of the convective organization and mean states to interactive radiation, interactive surface fluxes, and evaporation of rain. These simulations are compared to self-aggregation seen in the same model configured to run in idealized radiative-convective equilibriu...

  9. CDM Convective Forecast Planning guidance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CDM Convective Forecast Planning (CCFP) guidance product provides a foreast of en-route aviation convective hazards. The forecasts are updated every 2 hours and...

  10. Presentation on Tropical Mesoscale convective Systems and ...

    Indian Academy of Sciences (India)

    IAS Admin

    Shallow convection- 70% of the storm heights are below 6 km. ♢ Deep convection ... Decay convection, the convective top is found at a higher altitude than deep .... Stratospheric Fountain – Two step process. Warm tropopause- preferable for.

  11. Convective overshooting in stars

    NARCIS (Netherlands)

    Andrássy, R.

    2015-01-01

    Numerous observations provide evidence that the standard picture, in which convective mixing is limited to the unstable layers of a star, is incomplete. The mixing layers in real stars are significantly more extended than what the standard models predict. Some of the observations require changing

  12. Loop Transfer Matrix and Loop Quantum Mechanics

    International Nuclear Information System (INIS)

    Savvidy, George K.

    2000-01-01

    The gonihedric model of random surfaces on a 3d Euclidean lattice has equivalent representation in terms of transfer matrix K(Q i ,Q f ), which describes the propagation of loops Q. We extend the previous construction of the loop transfer matrix to the case of nonzero self-intersection coupling constant κ. We introduce the loop generalization of Fourier transformation which allows to diagonalize transfer matrices, that depend on symmetric difference of loops only and express all eigenvalues of 3d loop transfer matrix through the correlation functions of the corresponding 2d statistical system. The loop Fourier transformation allows to carry out the analogy with quantum mechanics of point particles, to introduce conjugate loop momentum P and to define loop quantum mechanics. We also consider transfer matrix on 4d lattice which describes propagation of memebranes. This transfer matrix can also be diagonalized by using the generalized Fourier transformation, and all its eigenvalues are equal to the correlation functions of the corresponding 3d statistical system. In particular the free energy of the 4d membrane system is equal to the free energy of 3d gonihedric system of loops and is equal to the free energy of 2d Ising model. (author)

  13. Convective Propagation Characteristics Using a Simple Representation of Convective Organization

    Science.gov (United States)

    Neale, R. B.; Mapes, B. E.

    2016-12-01

    Observed equatorial wave propagation is intimately linked to convective organization and it's coupling to features of the larger-scale flow. In this talk we a use simple 4 level model to accommodate vertical modes of a mass flux convection scheme (shallow, mid-level and deep). Two paradigms of convection are used to represent convective processes. One that has only both random (unorganized) diagnosed fluctuations of convective properties and one with organized fluctuations of convective properties that are amplified by previously existing convection and has an explicit moistening impact on the local convecting environment We show a series of model simulations in single-column, 2D and 3D configurations, where the role of convective organization in wave propagation is shown to be fundamental. For the optimal choice of parameters linking organization to local atmospheric state, a broad array of convective wave propagation emerges. Interestingly the key characteristics of propagating modes are the low-level moistening followed by deep convection followed by mature 'large-scale' heating. This organization structure appears to hold firm across timescales from 5-day wave disturbances to MJO-like wave propagation.

  14. Active house

    DEFF Research Database (Denmark)

    Eriksen, Kurt Emil; Olesen, Gitte Gylling Hammershøj

    Formålet med dette abstrakt er at illustrere, at huse kan være konstrueret til at basere sig udelukkende på vedvarende energikilder og samtidig være CO2-neutrale og producere mere energi end de forbruger. Active House Visionen undersøger disse muligheder i otte demonstration huse i fem forskellige...

  15. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  16. Concepts of magnetospheric convection

    International Nuclear Information System (INIS)

    Vasyliunas, V.M.

    1975-01-01

    Magnetospheric physics, which grew out of attempts to understand the space environment of the Earth, is becoming increasingly applicable to other systems in the Universe. Among the planets, in addition to the Earth, Jupiter, Mercury, Mars and (in a somewhat different way) Venus are now known to have magnetospheres. The magnetospheres of pulsars have been regarded as an essential part of the pulsar phenomenon. Other astrophysical systems, such as supernova remnant shells or magnetic stars and binary star systems, may be describable as magnetospheres. The major concepts of magnetospheric physics thus need to be formulated in a general way not restricted to the geophysical context in which they may have originated. Magnetospheric convection has been one of the most important and fruitful concepts in the study of the Earth's magnetosphere. This paper describes the basic theoretical notions of convection in a manner applicable to magnetospheres generally and discusses the relative importance of convective corotational motions, with particular reference to the comparison of the Earth and Jupiter. (Auth.)

  17. The Brownian loop soup

    OpenAIRE

    Lawler, Gregory F.; Werner, Wendelin

    2003-01-01

    We define a natural conformally invariant measure on unrooted Brownian loops in the plane and study some of its properties. We relate this measure to a measure on loops rooted at a boundary point of a domain and show how this relation gives a way to ``chronologically add Brownian loops'' to simple curves in the plane.

  18. Smart Houses

    Science.gov (United States)

    1987-01-01

    GWS takes plans for a new home and subjects them to intensive computerized analysis that does 10,000 calculations relative to expected heat loss and heat gain, then provides specifications designed specifically for each structure as to heating, cooling, ventilation and insulation. As construction progresses, GWS inspects the work of the electrical, plumbing and insulation contractors and installs its own Smart House Radiant Barrier. On completion of the home, GWS technicians use a machine that creates a vacuum in the house and enables computer calculation of the air exchanged, a measure of energy efficiency. Key factor is the radiant barrier, borrowed from the Apollo program. This is an adaptation of a highly effective aluminized heat shield as a radiation barrier holding in or keeping out heat, cold air and water vapor.

  19. Forced-convection boiling tests performed in parallel simulated LMR fuel assemblies

    International Nuclear Information System (INIS)

    Rose, S.D.; Carbajo, J.J.; Levin, A.E.; Lloyd, D.B.; Montgomery, B.H.; Wantland, J.L.

    1985-01-01

    Forced-convection tests have been carried out using parallel simulated Liquid Metal Reactor fuel assemblies in an engineering-scale sodium loop, the Thermal-Hydraulic Out-of-Reactor Safety facility. The tests, performed under single- and two-phase conditions, have shown that for low forced-convection flow there is significant flow augmentation by thermal convection, an important phenomenon under degraded shutdown heat removal conditions in an LMR. The power and flows required for boiling and dryout to occur are much higher than decay heat levels. The experimental evidence supports analytical results that heat removal from an LMR is possible with a degraded shutdown heat removal system

  20. On the Reconstruction of the Convection Pattern Below an Active Region of Solar Corona

    International Nuclear Information System (INIS)

    Pirot, Dorian; Gaudet, Jonathan; Vincent, Alain

    2012-01-01

    In order to better understand magneto-convective patterns and flux emergence, we use the Nudging Back and Forth, a data assimilation method with an anelastic convection model to reconstruct the convection zone below a solar active region from observed solar surface magnetograms. To mimic photosphere, vector magnetograms are computed using force free hypothesis. We find that the observed arcade system of AR9077-20000714 ( t he slinky ) of magnetic lines is actually formed by Ω and U loops generated in the convection zone. We generate temperature maps at top of the convective zone and find that high magnetic fields on either sides of the neutral line produce a local cooling by impeding the overturning motions.

  1. The radiation safety assessment of the heating loop of district heating reactors

    International Nuclear Information System (INIS)

    Liu Yuanzhong

    1993-01-01

    The district heating reactors are used to supply heating to the houses in cities. The concerned problems are whether the radioactive materials reach the heated houses through heating loop, and whether the safety of the dwellers can be ensured. In order to prevent radioactive materials getting into the heated houses, the district heating reactors have three loops, namely, primary loop, intermediate loop, and heating loop. In the paper, the measures of preventing radioactive materials getting into the heating loop are presented, and the possible sources of the radioactivity in the water of the intermediate loop and the heating loop are given. The regulatory aim limit of radioactive concentration in the water of the intermediate loop is put forward, which is 18.5 Bq/l. Assuming that specific radioactivity of the water of contaminated intermediate loop is up to 18.5 Bq/l, the maximum concentration of radionuclides in water of the heating loop is calculated for the normal operation and the accident of district heating reactor. The results show that the maximum possible concentration is 5.7 x 10 -3 Bq/l. The radiation safety assessment of the heating loop is made out. The conclusions are that the district heating reactors do not bring any harmful impact to the dwellers, and the safety of the dwellers can be safeguarded completely

  2. Bidispersive-inclined convection

    Science.gov (United States)

    Mulone, Giuseppe; Straughan, Brian

    2016-01-01

    A model is presented for thermal convection in an inclined layer of porous material when the medium has a bidispersive structure. Thus, there are the usual macropores which are full of a fluid, but there are also a system of micropores full of the same fluid. The model we employ is a modification of the one proposed by Nield & Kuznetsov (2006 Int. J. Heat Mass Transf. 49, 3068–3074. (doi:10.1016/j.ijheatmasstransfer.2006.02.008)), although we consider a single temperature field only. PMID:27616934

  3. Experimental StudyHigh Altitude Forced Convective Cooling of Electromechanical Actuation Systems

    Science.gov (United States)

    2016-01-01

    34 Massachusetts Institute of Technology , 1989. [3] FedBizOps.Gov, " Integrated Vehicle Energy Technology (INVENT) Development Program for the 6th...AFRL-RQ-WP-TR-2016-0043 EXPERIMENTAL STUDY—HIGH ALTITUDE FORCED CONVECTIVE COOLING OF ELECTROMECHANICAL ACTUATION SYSTEMS Evan M. Racine...TITLE AND SUBTITLE EXPERIMENTAL STUDY—HIGH ALTITUDE FORCED CONVECTIVE COOLING OF ELECTROMECHANICAL ACTUATION SYSTEMS 5a. CONTRACT NUMBER In-house

  4. Radon concentration in a house of Calvados

    International Nuclear Information System (INIS)

    Leleyter, L.; Riffault, B.; Mazenc, B.

    2010-01-01

    Recent studies indicate a link between the risk of lung cancer and residential radon exposure. However, in France, awareness of this problem was made relatively late. Accordingly this study examines the radon concentration in a private home in Calvados (Normandy region). Findings show that the presence of a fireplace in a house can accelerate radon convective transfer, and that simple adjustments to interior and exterior accommodation can significantly reduce radon concentrations in the home. (authors)

  5. Renormalization of loop functions for all loops

    International Nuclear Information System (INIS)

    Brandt, R.A.; Neri, F.; Sato, M.

    1981-01-01

    It is shown that the vacuum expectation values W(C 1 ,xxx, C/sub n/) of products of the traces of the path-ordered phase factors P exp[igcontour-integral/sub C/iA/sub μ/(x)dx/sup μ/] are multiplicatively renormalizable in all orders of perturbation theory. Here A/sub μ/(x) are the vector gauge field matrices in the non-Abelian gauge theory with gauge group U(N) or SU(N), and C/sub i/ are loops (closed paths). When the loops are smooth (i.e., differentiable) and simple (i.e., non-self-intersecting), it has been shown that the generally divergent loop functions W become finite functions W when expressed in terms of the renormalized coupling constant and multiplied by the factors e/sup -K/L(C/sub i/), where K is linearly divergent and L(C/sub i/) is the length of C/sub i/. It is proved here that the loop functions remain multiplicatively renormalizable even if the curves have any finite number of cusps (points of nondifferentiability) or cross points (points of self-intersection). If C/sub γ/ is a loop which is smooth and simple except for a single cusp of angle γ, then W/sub R/(C/sub γ/) = Z(γ)W(C/sub γ/) is finite for a suitable renormalization factor Z(γ) which depends on γ but on no other characteristic of C/sub γ/. This statement is made precise by introducing a regularization, or via a loop-integrand subtraction scheme specified by a normalization condition W/sub R/(C-bar/sub γ/) = 1 for an arbitrary but fixed loop C-bar/sub γ/. Next, if C/sub β/ is a loop which is smooth and simple except for a cross point of angles β, then W(C/sub β/) must be renormalized together with the loop functions of associated sets S/sup i//sub β/ = ]C/sup i/ 1 ,xxx, C/sup i//sub p/i] (i = 2,xxx,I) of loops C/sup i//sub q/ which coincide with certain parts of C/sub β/equivalentC 1 1 . Then W/sub R/(S/sup i//sub β/) = Z/sup i/j(β)W(S/sup j//sub β/) is finite for a suitable matrix Z/sup i/j

  6. Sydney Opera House Rise

    DEFF Research Database (Denmark)

    2013-01-01

    Sydney Opera House Exhibition (2013) A CITA research and exhibition project, for Sydney Opera House exhibition "Danish Design at the House".......Sydney Opera House Exhibition (2013) A CITA research and exhibition project, for Sydney Opera House exhibition "Danish Design at the House"....

  7. Housing markets and housing policies in India

    OpenAIRE

    Tiwari, Piyush; Rao, Jyoti

    2016-01-01

    Issues of housing in India are synonymous with ignorance of housing in active government involvement at the policy and program formulation levels. They are also due to the problems that unplanned urbanization, income disparity, poverty, illiteracy, and unemployment brought. These issues extenuated the housing problem, causing a housing shortage of 51 million in 2011. Though India has a long history of establishing policies, programs, and institutions to cater to housing, without allocating ad...

  8. Design of a pressurized water loop heated by electric resistances

    International Nuclear Information System (INIS)

    Ribeiro, S.V.G.

    1981-01-01

    A pressurized water loop design is presented. Its operating pressure is 420 psi and we seek to simulate qualitatively some thermo-hydraulic phenomena of PWR reactors. The primary circuit simulator consists basically of two elements: 1)the test section housing 16 electric resistences dissipating a total power of 100 Kw; 2)the loop built of SCH40S 304L steel piping, consisting of the pump, a heat exchanger and the pressurizer. (Author) [pt

  9. Random walk loop soup

    OpenAIRE

    Lawler, Gregory F.; Ferreras, José A. Trujillo

    2004-01-01

    The Brownian loop soup introduced in Lawler and Werner (2004) is a Poissonian realization from a sigma-finite measure on unrooted loops. This measure satisfies both conformal invariance and a restriction property. In this paper, we define a random walk loop soup and show that it converges to the Brownian loop soup. In fact, we give a strong approximation result making use of the strong approximation result of Koml\\'os, Major, and Tusn\\'ady. To make the paper self-contained, we include a proof...

  10. On loop extensions and cohomology of loops

    OpenAIRE

    Benítez, Rolando Jiménez; Meléndez, Quitzeh Morales

    2015-01-01

    In this paper are defined cohomology-like groups that classify loop extensions satisfying a given identity in three variables for association identities, and in two variables for the case of commutativity. It is considered a large amount of identities. This groups generalize those defined in works of Nishigori [2] and of Jhonson and Leedham-Green [4]. It is computed the number of metacyclic extensions for trivial action of the quotient on the kernel in one particular case for left Bol loops a...

  11. Neutron transport in irradiation loops (IRENE loop)

    International Nuclear Information System (INIS)

    Sarsam, Maher.

    1980-09-01

    This thesis is composed of two parts with different aspects. Part one is a technical description of the loop and its main ancillary facilities as well as of the safety and operational regulations. The measurement methods on the model of the ISIS reactor and on the loop in the OSIRIS reactor are described. Part two deals with the possibility of calculating the powers dissipated by each rod of the fuel cluster, using appropriate computer codes, not only in the reflector but also in the core and to suggest a method of calculation [fr

  12. Convection in Porous Media

    CERN Document Server

    Nield, Donald A

    2013-01-01

    Convection in Porous Media, 4th Edition, provides a user-friendly introduction to the subject, covering a wide range of topics, such as fibrous insulation, geological strata, and catalytic reactors. The presentation is self-contained, requiring only routine mathematics and the basic elements of fluid mechanics and heat transfer. The book will be of use not only to researchers and practicing engineers as a review and reference, but also to graduate students and others entering the field. The new edition features approximately 1,750 new references and covers current research in nanofluids, cellular porous materials, strong heterogeneity, pulsating flow, and more. Recognized as the standard reference in the field Includes a comprehensive, 250-page reference list Cited over 2300 times to date in its various editions Serves as an introduction for those entering the field and as a comprehensive reference for experienced researchers Features new sections on nanofluids, carbon dioxide sequestration, and applications...

  13. Temperature-Driven Convection

    Science.gov (United States)

    Bohan, Richard J.; Vandegrift, Guy

    2003-02-01

    Warm air aloft is stable. This explains the lack of strong winds in a warm front and how nighttime radiative cooling can lead to motionless air that can trap smog. The stability of stratospheric air can be attributed to the fact that it is heated from above as ultraviolet radiation strikes the ozone layer. On the other hand, fluid heated from below is unstable and can lead to Bernard convection cells. This explains the generally turbulent nature of the troposphere, which receives a significant fraction of its heat directly from the Earth's warmer surface. The instability of cold fluid aloft explains the violent nature of a cold front, as well as the motion of Earth's magma, which is driven by radioactive heating deep within the Earth's mantle. This paper describes how both effects can be demonstrated using four standard beakers, ice, and a bit of food coloring.

  14. Convection in porous media

    CERN Document Server

    Nield, Donald A

    1992-01-01

    This book provides a user-friendly introduction to the topic of convection in porous media The authors as- sume that the reader is familiar with the basic elements of fluid mechanics and heat transfer, but otherwise the book is self-contained The book will be useful both as a review (for reference) and as a tutorial work, suitable as a textbook in a graduate course or seminar The book brings into perspective the voluminous research that has been performed during the last two decades The field has recently exploded because of worldwide concern with issues such as energy self-sufficiency and pollution of the environment Areas of application include the insulation of buildings and equipment, energy storage and recovery, geothermal reservoirs, nuclear waste disposal, chemical reactor engineering, and the storage of heat-generating materials such as grain and coal Geophysical applications range from the flow of groundwater around hot intrusions to the stability of snow against avalanches

  15. Water loop for training

    International Nuclear Information System (INIS)

    Moeller, S.V.

    1983-02-01

    The procedures used to operate the water loop of the Institute of Nuclear Enginering (IEN) in Brazil are presented. The aim is to help future operators of the training water loop in the operation technique and in a better comprehension of the phenomena occured during the execution of an experience. (E.G.) [pt

  16. Stellar convection and dynamo theory

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, R L

    1989-10-01

    In considering the large scale stellar convection problem the outer layers of a star are modelled as two co-rotating plane layers coupled at a fluid/fluid interface. Heating from below causes only the upper fluid to convect, although this convection can penetrate into the lower fluid. Stability analysis is then used to find the most unstable mode of convection. With parameters appropriate to the Sun the most unstable mode is steady convection in thin cells (aspect ratio {approx equal} 0.2) filling the convection zone. There is negligible vertical motion in the lower fluid, but considerable thermal penetration, and a large jump in helicity at the interface, which has implications for dynamo theory. An {alpha}{omega} dynamo is investigated in isolation from the convection problem. Complexity is included by allowing both latitudinal and time dependence in the magnetic fields. The nonlinear dynamics of the resulting partial differential equations are analysed in considerable detail. On varying the main control parameter D (the dynamo number), many transitions of behaviour are found involving many forms of time dependence, but not chaos. Further, solutions which break equatorial symmetry are common and provide a theoretical explanation of solar observations which have this symmetry. Overall the behaviour was more complicated than expected. In particular, there were multiple stable solutions at fixed D, meaning that similar stars can have very different magnetic patterns, depending upon their history. (author).

  17. Modeling the Solar Convective Dynamo and Emerging Flux

    Science.gov (United States)

    Fan, Y.

    2017-12-01

    Significant advances have been made in recent years in global-scale fully dynamic three-dimensional convective dynamo simulations of the solar/stellar convective envelopes to reproduce some of the basic features of the Sun's large-scale cyclic magnetic field. It is found that the presence of the dynamo-generated magnetic fields plays an important role for the maintenance of the solar differential rotation, without which the differential rotation tends to become anti-solar (with a faster rotating pole instead of the observed faster rotation at the equator). Convective dynamo simulations are also found to produce emergence of coherent super-equipartition toroidal flux bundles with a statistically significant mean tilt angle that is consistent with the mean tilt of solar active regions. The emerging flux bundles are sheared by the giant cell convection into a forward leaning loop shape with its leading side (in the direction of rotation) pushed closer to the strong downflow lanes. Such asymmetric emerging flux pattern may lead to the observed asymmetric properties of solar active regions.

  18. Low energy housing in Ticino - The 'Vitali-Velti' house

    Energy Technology Data Exchange (ETDEWEB)

    Pahud, D.; Generelli, M. [SUPSI-DCT/LEEE-UREC, Trevano-Canobbio (Switzerland); Velti, A; Vitali, B. [architetto, Monte Carasso (Switzerland)

    2003-02-15

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at work done concerning low energy consumption housing in southern Switzerland. Thanks to large windows in the south-east facade and a well insulated building envelope, the passive solar gains are quoted as providing significant contributions to heating. The remaining heating requirements are covered by a closed fireplace and an electric radiator. Heat is distributed by free convection inside the house, A double-flux ventilation system with heat recovery ensures air renewal (3 volumes per day). Each house has a solar hot water system with electric auxiliary energy supply. Space heating requirements are discussed and compared with the standard values as defined in Swiss energy standards and the conventional auxiliary space heating energy required for the houses is noted.

  19. The convection patterns in microemulsions

    International Nuclear Information System (INIS)

    Korneta, W.; Lopez Quintela, M.A.; Fernandez Novoa, A.

    1991-07-01

    The Rayleigh-Benard convection in the microemulsion consisting of water (7.5%), cyclohexan (oil-61.7%) and diethylenglycolmonobutylether (surfactant-30.8%) is studied from the onset of convection to the phase separation. The five classes of convection patterns are observed and recorded on the video: localized travelling waves, travelling waves, travelling waves and localized steady rolls, steady rolls and steady polygons. The Fourier transforms and histograms of these patterns are presented. The origin of any pattern is discussed. The intermittent behaviour close to the phase separation was observed. Possible applications of the obtained results are suggested. (author). 6 refs, 4 figs

  20. Transient heat transfer for forced convection flow of helium gas

    International Nuclear Information System (INIS)

    Liu, Qiusheng; Fukuda, Katsuya; Sasaki, Kenji; Yamamoto, Manabu

    1999-01-01

    Transient heat transfer coefficients for forced convection flow of helium gas over a horizontal cylinder were measured using a forced convection test loop. The platinum heater with a diameter of 1.0 mm was heated by electric current with an exponential increase of Q 0 exp(t/τ). It was clarified that the heat transfer coefficient approaches the steady-state one for the period τ over 1 s, and it becomes higher for the period of τ shorter than 1 s. The transient heat transfer shows less dependent on the gas flowing velocity when the period becomes very shorter. Semi-empirical correlations for steady-state and transient heat transfer were developed based on the experimental data. (author)

  1. United States housing, 2012

    Science.gov (United States)

    Delton Alderman

    2013-01-01

    Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing completions for single and multifamily units, and sales and construction. This report will be updated annually.

  2. American Housing Survey (AHS)

    Data.gov (United States)

    Department of Housing and Urban Development — The AHS is the largest, regular national housing sample survey in the United States. The U.S. Census Bureau conducts the AHS to obtain up-to-date housing statistics...

  3. TARP Monthly Housing Scorecard

    Data.gov (United States)

    Department of the Treasury — Treasury and the U.S. Department of Housing and Urban Development (HUD) jointly produce a Monthly Housing Scorecard on the health of the nation’s housing market. The...

  4. Convection in the Labrador Sea

    National Research Council Canada - National Science Library

    Davis, R

    1997-01-01

    The long-term goal of this grant was to describe the process of deep oceanic convection well enough to provide critical tests of, and guidance to, models used to predict subsurface ocean conditions...

  5. Large lithium loop experience

    International Nuclear Information System (INIS)

    Kolowith, R.; Owen, T.J.; Berg, J.D.; Atwood, J.M.

    1981-10-01

    An engineering design and operating experience of a large, isothermal, lithium-coolant test loop are presented. This liquid metal coolant loop is called the Experimental Lithium System (ELS) and has operated safely and reliably for over 6500 hours through September 1981. The loop is used for full-scale testing of components for the Fusion Materials Irradiation Test (FMIT) Facility. Main system parameters include coolant temperatures to 430 0 C and flow to 0.038 m 3 /s (600 gal/min). Performance of the main pump, vacuum system, and control system is discussed. Unique test capabilities of the ELS are also discussed

  6. Convection-enhanced water evaporation

    OpenAIRE

    B. M. Weon; J. H. Je; C. Poulard

    2011-01-01

    Water vapor is lighter than air; this can enhance water evaporation by triggering vapor convection but there is little evidence. We directly visualize evaporation of nanoliter (2 to 700 nL) water droplets resting on silicon wafer in calm air using a high-resolution dual X-ray imaging method. Temporal evolutions of contact radius and contact angle reveal that evaporation rate linearly changes with surface area, indicating convective (instead of diffusive) evaporation in nanoliter water droplet...

  7. MODELING THE RISE OF FIBRIL MAGNETIC FIELDS IN FULLY CONVECTIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Maria A.; Browning, Matthew K., E-mail: mweber@astro.ex.ac.uk [Department of Physics and Astronomy, University of Exeter, Stocker Road, EX4 4QL Exeter (United Kingdom)

    2016-08-20

    Many fully convective stars exhibit a wide variety of surface magnetism, including starspots and chromospheric activity. The manner by which bundles of magnetic field traverse portions of the convection zone to emerge at the stellar surface is not especially well understood. In the solar context, some insight into this process has been gleaned by regarding the magnetism as consisting partly of idealized thin flux tubes (TFTs). Here we present the results of a large set of TFT simulations in a rotating spherical domain of convective flows representative of a 0.3 M {sub ⊙} main-sequence star. This is the first study to investigate how individual flux tubes in such a star might rise under the combined influence of buoyancy, convection, and differential rotation. A time-dependent hydrodynamic convective flow field, taken from separate 3D simulations calculated with the anelastic equations, impacts the flux tube as it rises. Convective motions modulate the shape of the initially buoyant flux ring, promoting localized rising loops. Flux tubes in fully convective stars have a tendency to rise nearly parallel to the rotation axis. However, the presence of strong differential rotation allows some initially low-latitude flux tubes of moderate strength to develop rising loops that emerge in the near-equatorial region. Magnetic pumping suppresses the global rise of the flux tube most efficiently in the deeper interior and at lower latitudes. The results of these simulations aim to provide a link between dynamo-generated magnetic fields, fluid motions, and observations of starspots for fully convective stars.

  8. White House Communications Agency

    National Research Council Canada - National Science Library

    Gimble, Thomas

    1995-01-01

    The Chairman, House Committee on Government Reform and Oversight; the Chairman, House Subcommittee on National Security, International Affairs, and Criminal Justice, Committee on Government Reform and Oversight...

  9. Natively unstructured loops differ from other loops.

    Directory of Open Access Journals (Sweden)

    Avner Schlessinger

    2007-07-01

    Full Text Available Natively unstructured or disordered protein regions may increase the functional complexity of an organism; they are particularly abundant in eukaryotes and often evade structure determination. Many computational methods predict unstructured regions by training on outliers in otherwise well-ordered structures. Here, we introduce an approach that uses a neural network in a very different and novel way. We hypothesize that very long contiguous segments with nonregular secondary structure (NORS regions differ significantly from regular, well-structured loops, and that a method detecting such features could predict natively unstructured regions. Training our new method, NORSnet, on predicted information rather than on experimental data yielded three major advantages: it removed the overlap between testing and training, it systematically covered entire proteomes, and it explicitly focused on one particular aspect of unstructured regions with a simple structural interpretation, namely that they are loops. Our hypothesis was correct: well-structured and unstructured loops differ so substantially that NORSnet succeeded in their distinction. Benchmarks on previously used and new experimental data of unstructured regions revealed that NORSnet performed very well. Although it was not the best single prediction method, NORSnet was sufficiently accurate to flag unstructured regions in proteins that were previously not annotated. In one application, NORSnet revealed previously undetected unstructured regions in putative targets for structural genomics and may thereby contribute to increasing structural coverage of large eukaryotic families. NORSnet found unstructured regions more often in domain boundaries than expected at random. In another application, we estimated that 50%-70% of all worm proteins observed to have more than seven protein-protein interaction partners have unstructured regions. The comparative analysis between NORSnet and DISOPRED2 suggested

  10. Introduction to Loop Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Loop Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. This course will discuss operating principles and performance characteristics of a loop heat pipe. Topics include: 1) pressure profiles in the loop; 2) loop operating temperature; 3) operating temperature control; 4) loop startup; 4) loop shutdown; 5) loop transient behaviors; 6) sizing of loop components and determination of fluid inventory; 7) analytical modeling; 8) examples of flight applications; and 9) recent LHP developments.

  11. Diffusion of Wilson loops

    International Nuclear Information System (INIS)

    Brzoska, A.M.; Lenz, F.; Thies, M.; Negele, J.W.

    2005-01-01

    A phenomenological analysis of the distribution of Wilson loops in SU(2) Yang-Mills theory is presented in which Wilson loop distributions are described as the result of a diffusion process on the group manifold. It is shown that, in the absence of forces, diffusion implies Casimir scaling and, conversely, exact Casimir scaling implies free diffusion. Screening processes occur if diffusion takes place in a potential. The crucial distinction between screening of fundamental and adjoint loops is formulated as a symmetry property related to the center symmetry of the underlying gauge theory. The results are expressed in terms of an effective Wilson loop action and compared with various limits of SU(2) Yang-Mills theory

  12. Blind loop syndrome

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001146.htm Blind loop syndrome To use the sharing features on ... Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David ...

  13. Mashup the OODA Loop

    National Research Council Canada - National Science Library

    Heier, Jeffrey E

    2008-01-01

    ...) processes via the Observe, Orient, Decide, and Act (OODA) Loop concept. As defined by Wikipedia, a mashup is a Website or application that combines the content from more than one source into an integrated presentation...

  14. Reactor loops at Chalk River

    International Nuclear Information System (INIS)

    Sochaski, R.O.

    1962-07-01

    This report describes broadly the nine in-reactor loops, and their components, located in and around the NRX and NRU reactors at Chalk River. First an introduction and general description is given of the loops and their function, supplemented with a table outlining some loop specifications and nine simplified flow sheets, one for each individual loop. The report then proceeds to classify each loop into two categories, the 'main loop circuit' and the 'auxiliary circuit', and descriptions are given of each circuit's components in turn. These components, in part, are comprised of the main loop pumps, the test section, loop heaters, loop coolers, delayed-neutron monitors, surge tank, Dowtherm coolers, loop piping. Here again photographs, drawings and tables are included to provide a clearer understanding of the descriptive literature and to include, in tables, some specifications of the more important components in each loop. (author)

  15. Dechanneling by dislocation loops

    International Nuclear Information System (INIS)

    Chalant, Gerard.

    1976-09-01

    Ion implantation always induces the creation of dislocation loops. When the damage profile is determined by a backscattering technique, the dechanneling by these loops is implicitely at the origin of these measurements. The dechanneling of alpha particles by dislocation loops produced by the coalescence of quenched-in vacancies in aluminium is studied. The dechanneling and the concentration of loops were determined simultaneously. The dechanneling width around dislocation was found equal to lambda=6A, both for perfect and imperfect loops having a mean diameter d=250A. In the latter case, a dechanneling probability chi=0.34 was determined for the stacking fault, in good agreement with previous determination in gold. A general formula is proposed which takes into account the variation of lambda with the curvature (or the diameter d) of the loops. Finally, by a series of isothermal anneals, the self-diffusion energy ΔH of aluminium was measured. The value obtained ΔH=1.32+-0.10eV is in good agreement with the values obtained by other methods [fr

  16. Family Open House

    Science.gov (United States)

    Search Family Open House Join us for an afternoon of science fun. The Fermilab Family Open House is a party for children of all ages to learn about the world of physics. The Open House is supported by Open House? Check out our YouTube video to learn more! Explore physics concepts with hands-on

  17. Investigation of combined free and forced convection in a 2 x 6 rod bundle during controlled flow transients

    International Nuclear Information System (INIS)

    Bates, J.M.; Khan, E.U.

    1980-10-01

    An experimental study was performed to obtain local fluid velocity and temperature measurements in the mixed (combined free and forced) convection regime for specific flow coastdown transients. A brief investigation of steady-state flows for the purely free-convection regime was also completed. The study was performed using an electrically heated 2 x 6 rod bundle contained in a flow housing. In addition a transient data base was obtained for evaluating the COBRA-WC thermal-hydraulic computer program

  18. Mantle Convection on Modern Supercomputers

    Science.gov (United States)

    Weismüller, J.; Gmeiner, B.; Huber, M.; John, L.; Mohr, M.; Rüde, U.; Wohlmuth, B.; Bunge, H. P.

    2015-12-01

    Mantle convection is the cause for plate tectonics, the formation of mountains and oceans, and the main driving mechanism behind earthquakes. The convection process is modeled by a system of partial differential equations describing the conservation of mass, momentum and energy. Characteristic to mantle flow is the vast disparity of length scales from global to microscopic, turning mantle convection simulations into a challenging application for high-performance computing. As system size and technical complexity of the simulations continue to increase, design and implementation of simulation models for next generation large-scale architectures is handled successfully only in an interdisciplinary context. A new priority program - named SPPEXA - by the German Research Foundation (DFG) addresses this issue, and brings together computer scientists, mathematicians and application scientists around grand challenges in HPC. Here we report from the TERRA-NEO project, which is part of the high visibility SPPEXA program, and a joint effort of four research groups. TERRA-NEO develops algorithms for future HPC infrastructures, focusing on high computational efficiency and resilience in next generation mantle convection models. We present software that can resolve the Earth's mantle with up to 1012 grid points and scales efficiently to massively parallel hardware with more than 50,000 processors. We use our simulations to explore the dynamic regime of mantle convection and assess the impact of small scale processes on global mantle flow.

  19. An experimental approach to improve the basin type solar still using an integrated natural circulation loop

    International Nuclear Information System (INIS)

    Rahmani, Ahmed; Boutriaa, Abdelouahab; Hadef, Amar

    2015-01-01

    Highlights: • A new experimental approach to improve the conventional solar still performances is proposed. • A passive natural circulation loop is integrated to the conventional solar still. • Natural circulation of humid-air in a closed loop is studied by the present study. • Natural circulation capability in driving air convection in the still was demonstrated. • Air convection created inside the still increase the evaporation heat and mass transfer. - Abstract: In this paper, a new experimental approach is proposed to enhance the performances of the conventional solar still using the natural circulation effect inside the still. The idea consists in generating air flow by a rectangular natural circulation loop appended to the rear side of the still. The proposed still was tested during summer period and the experimental data presented in this paper concerns four typical days. The convective heat transfer coefficient is evaluated and compared with Dunkle’s model. The comparison shows that convective heat transfer is considerably improved by the air convection created inside the still. The natural circulation phenomenon in the still is studied and a good agreement between the experimental data and Vijajan’s laminar correlation is found. Therefore, natural circulation phenomenon is found to have a good effect on the still performances where the still daily productivity is of 3.72 kg/m 2 and the maximum efficiency is of 45.15%

  20. Innova House - Ottawa`s advanced house

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-31

    A pilot program was developed to provide the housing industry with a means to field test innovative technologies, products and building systems, and to evaluate their overall performance. Under Canada`s Advanced House Program, ten demonstration houses were designed, built and monitored. Ottawa`s Innova House, was one of the ten houses built for this program. The innovative energy saving features of the house included (1) air distribution with small diameter ducts and an electronically commutated motor, a 2.6 kW grid-connected photovoltaic system, (3) an energy recovery ventilator (ERV) with free-cooling mode, (4) a 94 per cent efficient integrated gas heating and hot water system, (5) airtight drywall construction, (6) CFC-free exterior insulation, (7) a natural-gas-engine heat pump for air conditioning, (8) a prototype sealed combustion gas range and clothes dryer, and (9) a manifold plumbing system to conserve water. It was designed to consume one half of the energy consumed in an R-2000 home and one third of the energy of a conventional house. Several of the mechanical elements did not perform at expected levels, (lower than expected efficiencies from the heating and cooling systems and a malfunctioning ERV), nevertheless, overall performance of the house was still very close to the targets. The construction and operation of the house was described. tabs., figs.

  1. Convective behaviour in severe accidents

    International Nuclear Information System (INIS)

    Clement, C.F.

    1988-01-01

    The nature and magnitude of the hazard from radioactivity posed by a possible nuclear accident depend strongly on convective behaviour within and immediately adjacent to the plant in question. This behaviour depends upon the nature of the vapour-gas-aerosol mixture concerned, and can show unusual properties such as 'upside-down' convection in which hot mixtures fall and cold mixtures rise. Predictions and criteria as to the types of behaviour which could possibly occur are summarised. Possible applications to present reactors are considered, and ways in which presently expected convection could be drastically modified are described. In some circumstances these could be used to suppress the radioactive source term or to switch its effect between distant dilute contamination and severe local contamination. (author). 8 refs, 2 figs, 2 tabs

  2. Topology Optimization for Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    2011-01-01

    This report deals with the topology optimization of convection problems.That is, the aim of the project is to develop, implement and examine topology optimization of purely thermal and coupled thermomechanical problems,when the design-dependent eects of convection are taken into consideration.......This is done by the use of a self-programmed FORTRAN-code, which builds on an existing 2D-plane thermomechanical nite element code implementing during the course `41525 FEM-Heavy'. The topology optimizationfeatures have been implemented from scratch, and allows the program to optimize elastostatic mechanical...

  3. Experimental methods in natural convection

    International Nuclear Information System (INIS)

    Koster, J.N.

    1982-11-01

    Some common experimental techniques to determine local velocities and to visualize temperature fields in natural convection research are discussed. First the physics and practice of anemometers are discussed with emphasis put on optical anemometers. In the second and third case the physics and practice of the most developed interferometers are discussed; namely differential interferometry for visualization of temperature gradient fields and holographic interferometry for visualization of temperature fields. At the Institut fuer Reaktorbauelemente these three measuring techniques are applied for convection and pipe flow studies. (orig.) [de

  4. Essays on Housing Markets

    DEFF Research Database (Denmark)

    Bäckman, Claes

    In Denmark and in many countries around the world, housing markets are of considerable importance for households and policy-makers alike. As the boom and bust in the US and Danish housing market so aptly demonstrated, disruptions in the housing market potentially have wide-ranging consequences...... for individual households and for the aggregate economy. Housing is important because we all have to live somewhere, but also because it serves as a considerable source of both wealth and debt. As such, housing market policy can not only create vast benefits for many, but can also have substantial negative...... impacts for all, and should therefore be a topic of major interest for economists and policy makers alike. This Ph.D. thesis, entitled “Essays on Housing Markets”, analyzes the Danish housing market during the 2000s, with a focus on how policy changes affected house prices and how changes in house prices...

  5. The bishops and housing.

    Science.gov (United States)

    Shellabarger, Thomas

    2005-01-01

    According to Catholic social teaching, housing is not a commodity but a human right. To ensure that all people--especially low-income elderly and other vulnerable populations--have access to affordable housing, the church has established a variety of programs, services, and advocacy efforts. Much of this work is based on key concepts: preserving existing housing stock, creating new programs to provide more options for the underserved, empowering residents and communities to deal with housing issues, establishing partnerships to make organizations' efforts more successful, making housing affordable, and ending discrimination in housing. Although church ministries, community groups, the private sector, and other players must work together to find solutions to the housing crisis, federal leadership is essential. Especially with the housing affordability gap growing and the U.S. population aging, the federal government must provide the resources, leadership, and direction for effective housing solutions.

  6. Conformal boundary loop models

    International Nuclear Information System (INIS)

    Jacobsen, Jesper Lykke; Saleur, Hubert

    2008-01-01

    We study a model of densely packed self-avoiding loops on the annulus, related to the Temperley-Lieb algebra with an extra idempotent boundary generator. Four different weights are given to the loops, depending on their homotopy class and whether they touch the outer rim of the annulus. When the weight of a contractible bulk loop x≡q+q -1 element of (-2,2], this model is conformally invariant for any real weight of the remaining three parameters. We classify the conformal boundary conditions and give exact expressions for the corresponding boundary scaling dimensions. The amplitudes with which the sectors with any prescribed number and types of non-contractible loops appear in the full partition function Z are computed rigorously. Based on this, we write a number of identities involving Z which hold true for any finite size. When the weight of a contractible boundary loop y takes certain discrete values, y r ≡([r+1] q )/([r] q ) with r integer, other identities involving the standard characters K r,s of the Virasoro algebra are established. The connection with Dirichlet and Neumann boundary conditions in the O(n) model is discussed in detail, and new scaling dimensions are derived. When q is a root of unity and y=y r , exact connections with the A m type RSOS model are made. These involve precise relations between the spectra of the loop and RSOS model transfer matrices, valid in finite size. Finally, the results where y=y r are related to the theory of Temperley-Lieb cabling

  7. Situation-Based Housing

    DEFF Research Database (Denmark)

    Duelund Mortensen, Peder

    2011-01-01

    Presentation of urban housing research on flexible housing types in the Copenhagen Region: Theoretical background, methodology, analyse of spatial organization, interviews and results. Cases: Pærehaven in Ølby, Køge and M-house in Ørestad, Copenhagen......Presentation of urban housing research on flexible housing types in the Copenhagen Region: Theoretical background, methodology, analyse of spatial organization, interviews and results. Cases: Pærehaven in Ølby, Køge and M-house in Ørestad, Copenhagen...

  8. House Price, House Quality and Economic Growth

    NARCIS (Netherlands)

    De Vries, P.; Boelhouwer, P.J.

    2010-01-01

    The literature on housing markets suggest that periods of economic growth are characterised by a demand for better housing quality and increasing prices. The basic principles of the theory are that the short-run price fluctuations occur due to market imperfection, while over the long term, causality

  9. Active house concept versus passive House

    NARCIS (Netherlands)

    Zeiler, W.; Boxem, G.; Vehler, R.; Verhoeven, M.; Fremouw, M.

    2009-01-01

    The passive house concept is the present trend in energy efficient sustainable dwellings. Within the passive house concept every effort is made to minimize the energy use. Substantial savings can be achieved by passive energy systems, especially natural ventilation, summer shading and winter solar

  10. Segregation and convection in dendritic alloys

    Science.gov (United States)

    Poirier, D. R.

    1990-01-01

    Microsegregation in dentritic alloys is discussed, including solidification with and without thermal gradient, the convection of interdendritic liquid. The conservation of momentum, energy, and solute is considered. Directional solidification and thermosolutal convection are discussed.

  11. Effects of a Simple Convective Organization Scheme in a Two-Plume GCM

    Science.gov (United States)

    Chen, Baohua; Mapes, Brian E.

    2018-03-01

    A set of experiments is described with the Community Atmosphere Model (CAM5) using a two-plume convection scheme. To represent the differences of organized convection from General Circulation Model (GCM) assumptions of isolated plumes in uniform environments, a dimensionless prognostic "organization" tracer Ω is invoked to lend the second plume a buoyancy advantage relative to the first, as described in Mapes and Neale (2016). When low-entrainment plumes are unconditionally available (Ω = 1 everywhere), deep convection occurs too easily, with consequences including premature (upstream) rainfall in inflows to the deep tropics, excessive convective versus large-scale rainfall, poor relationships to the vapor field, stable bias in the mean state, weak and poor tropical variability, and midday peak in diurnal rainfall over land. Some of these are shown to also be characteristic of CAM4 with its separated deep and shallow convection schemes. When low-entrainment plumes are forbidden by setting Ω = 0 everywhere, some opposite problems can be discerned. In between those extreme cases, an interactive Ω driven by the evaporation of precipitation acts as a local positive feedback loop, concentrating deep convection: In areas of little recent rain, only highly entraining plumes can occur, unfavorable for rain production. This tunable mechanism steadily increases precipitation variance in both space and time, as illustrated here with maps, time-longitude series, and spectra, while avoiding some mean state biases as illustrated with process-oriented diagnostics such as conserved variable profiles and vapor-binned precipitation curves.

  12. Boiling Suppression in Convective Flow

    International Nuclear Information System (INIS)

    Aounallah, Y.

    2004-01-01

    The development of convective boiling heat transfer correlations and analytical models has almost exclusively been based on measurements of the total heat flux, and therefore on the overall two-phase heat transfer coefficient, when the well-known heat transfer correlations have often assumed additive mechanisms, one for each mode of heat transfer, convection and boiling. While the global performance of such correlations can readily be assessed, the predictive capability of the individual components of the correlation has usually remained elusive. This becomes important when, for example, developing mechanistic models for subcooled void formation based on the partitioning of the wall heat flux into a boiling and a convective component, or when extending a correlation beyond its original range of applications where the preponderance of the heat transfer mechanisms involved can be significantly different. A new examination of existing experimental heat transfer data obtained under fixed hydrodynamic conditions, whereby the local flow conditions are decoupled from the local heat flux, has allowed the unequivocal isolation of the boiling contribution over a broad range of thermodynamic qualities (0 to 0.8) for water at 7 MPa. Boiling suppression, as the quality increases, has consequently been quantified, thus providing valuable new insights on the functionality and contribution of boiling in convective flows. (author)

  13. Loop quantum gravity

    International Nuclear Information System (INIS)

    Pullin, J.

    2015-01-01

    Loop quantum gravity is one of the approaches that are being studied to apply the rules of quantum mechanics to the gravitational field described by the theory of General Relativity . We present an introductory summary of the main ideas and recent results. (Author)

  14. Blind Loop Syndrome

    Science.gov (United States)

    ... or scleroderma involving the small intestine History of radiation therapy to the abdomen Diabetes Diverticulosis of the small intestine Complications A blind loop can cause escalating problems, including: Poor absorption of fats. Bacteria in your small intestine break down the bile ...

  15. Improving Loop Dependence Analysis

    DEFF Research Database (Denmark)

    Jensen, Nicklas Bo; Karlsson, Sven

    2017-01-01

    Programmers can no longer depend on new processors to have significantly improved single-thread performance. Instead, gains have to come from other sources such as the compiler and its optimization passes. Advanced passes make use of information on the dependencies related to loops. We improve th...

  16. Cytokine loops driving senescence

    Czech Academy of Sciences Publication Activity Database

    Bartek, Jiří; Hodný, Zdeněk; Lukáš, Jan

    2008-01-01

    Roč. 10, č. 8 (2008), s. 887-889 ISSN 1465-7392 Institutional research plan: CEZ:AV0Z50520514 Keywords : cellular senescence * cytokines * autocrine feedback loop Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 17.774, year: 2008

  17. Loop Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Rovelli Carlo

    1998-01-01

    Full Text Available The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. Research in loop quantum gravity today forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained are: (i The computation of the physical spectra of geometrical quantities such as area and volume, which yields quantitative predictions on Planck-scale physics. (ii A derivation of the Bekenstein-Hawking black hole entropy formula. (iii An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, over-completeness of the loop basis, implementation of reality conditions have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.

  18. Keeping Energy Savings in the LOOP

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, Kristen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mercado, Andrea [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-11-01

    Mesa Lane Partners (MLP) partnered with the U.S. Department of Energy (DOE) to develop and implement solutions to a build a new, low-energy mixed-use building that consumes at least 50% less energy than requirements set by Energy Standard 90.1-2007 of the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE), the American National Standards Institute (ANSI), and the Illuminating Engineering Society of America (IESNA), as part of DOE’s Commercial Building Partnerships (CBP)3 Program. Lawrence Berkeley National Laboratory (LBNL) provided technical expertise in support of this DOE program. The privately developed 46,000-square-foot LOOP project, which is intended to provide affordable off-campus student housing in an underserved community next to University of California at Santa Barbara, will contain more than 7,000 square feet of retail space, a roof deck, an event space, a gym, and 48 apartments. The project developer, MLP, is aiming to exceed CBP requirement, targeting energy consumption that is at least 65% less than that required by the standard. If the LOOP meets this goal, it is expected to achieve Leadership in Energy and Environmental Design (LEED) Gold certification. To meet this goal, the project design incorporates a variety of energy efficiency measures (EEMs) that address the needs of the multiple use types that the project will house.

  19. Housing Inventory Count

    Data.gov (United States)

    Department of Housing and Urban Development — This report displays the data communities reported to HUD about the nature of their dedicated homeless inventory, referred to as their Housing Inventory Count (HIC)....

  20. Allegheny County Older Housing

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Older housing can impact the quality of the occupant's health in a number of ways, including lead exposure, housing quality, and factors that may exacerbate...

  1. Housing of Hobson's Choice

    DEFF Research Database (Denmark)

    Vestergaard, Hedvig

    2010-01-01

    This paper looks at policies implemented to improve troubled housing estates during more than two decades. Based on evaluations of implemented programmes and case studies the paper provides a basis for discussing a number of questions: • Why do we have troubled housing estates? • What...... is the definition of troubled housing estates? • Who lives on troubled housing estates? • Who owns and manages the troubled housing estates? • What have been the reasons behind improvement programmes for troubled housing estates? • What kind of improvement programmes have been implemented and with what kind...... of results? • Have improvement programmes changed the position of the estates on the local housing markets? • What are the changes in policies and results? • What are the perspectives for policy initiatives in the field of troubled housing estates?...

  2. Radon in houses

    International Nuclear Information System (INIS)

    Toohey, R.E.; Essling, M.A.; Markun, F.

    1985-01-01

    The purpose of this study is to determine the concentrations of 222 Rn and its short-lived daughter products in the air of single-family houses in the midwestern US. During the past year, more than 200 houses were added to the study, resulting in a total of more than 400 houses. So far, results are available for 270 of these houses, equally divided between the Chicago area and Bloomsburg, Pennsylvania. 6 refs

  3. Thermal and hydrodynamic characteristics of supercritical CO2 natural circulation in closed loops

    International Nuclear Information System (INIS)

    Chen, Lin; Deng, Bi-Li; Jiang, Bin; Zhang, Xin-Rong

    2013-01-01

    Highlights: ► We model thermosyphon heat transfer and stability with super-/trans-critical turbulence model incorporated. ► Potentials of super-/trans-critical CO 2 thermosyphon are confirmed. ► Three characteristics found: flow instability; high flow rate with density wave; heat transfer discrepancies. ► Major laws of system stability factors are different compared with traditional fluids. ► Traditional thermosyphon flow correlation has its limitations and deserves further development. -- Abstract: Natural convective flow of supercritical fluids has become a hot topic in engineering applications. Natural circulation thermosyphon using supercritical/trans-critical CO 2 can be a potential choice for effectively transportation of heat and mass without pumping devices. This paper presents a series of numerical investigations into the fundamental features in a supercritical/trans-critical CO 2 based natural circulation loop. New heat transport model aiming at trans-critical thermosyphon heat transfer and stability is proposed with supercritical/trans-critical turbulence model incorporated. In this study, the fundamentals include the basic flow and heat transfer behavior of the above loop, the effect of heat source temperature on system stability, the effect of loop diameter on natural convection supercritical CO 2 loop and its coupling effect with heat source temperature and the effect of constant changing heat input condition and system behavior evolution during unsteady input or failure conditions. The fundamental potentials of supercritical/trans-critical CO 2 based natural convection system are confirmed. Basic supercritical CO 2 closed loop flow and heat transfer behaviors are clarified. During this study, the CO 2 loop stability map are also put forward and introduced as an important feature of supercritical CO 2 system. Stability factors of natural convective trans-critical CO 2 flow and its implications on real system control are also discussed in

  4. Random walk loop soups and conformal loop ensembles

    NARCIS (Netherlands)

    van de Brug, T.; Camia, F.; Lis, M.

    2016-01-01

    The random walk loop soup is a Poissonian ensemble of lattice loops; it has been extensively studied because of its connections to the discrete Gaussian free field, but was originally introduced by Lawler and Trujillo Ferreras as a discrete version of the Brownian loop soup of Lawler and Werner, a

  5. Social Housing in Denmark

    DEFF Research Database (Denmark)

    Vestergaard, Hedvig; Scanlon, Kath J

    2014-01-01

    Social housing is a cornerstone in the Danish welfare society and is accessible for all households. By law, social housing must be rented at cost rents, which are based on historical costs; rents do not respond to market forces. Social housing aims to provide good standard, secure and affordable...... as social initiatives in the existing stock....

  6. Smart Solar Housing Renovation

    NARCIS (Netherlands)

    Ham, M.; Bruijn, de D.M.P.; Vos, S.J.H.; Weijers, K.A.M.; Straver, M.C.W.; Scartezzini, J.L.

    2009-01-01

    After World War II, the demand for houses in the Netherlands was enormous. Large housing construction programs were established in the fifties, sixties and seventies. Nowadays, these houses are facing some societal, economic and technological problems. On the other hand, many of the occupants are

  7. Dutch house price fundamentals

    NARCIS (Netherlands)

    Haffner, M.E.A.; de Vries, P.

    2009-01-01

    This paper discusses house price developments in the Netherlands, specifically focussing on the question whether current house prices in the Dutch owner-occupied market are likely to decrease. We analyse three aspects of the question based on a literature review: (1) whether there is a house price

  8. Thermal convection of a viscoplastic liquid with high Rayleigh and Bingham numbers

    Science.gov (United States)

    Vikhansky, A.

    2009-10-01

    We consider the effect of yield stress on the Rayleigh-Bénard convection of a viscoplastic material. First we consider the model problem of convection in a differentially heated loop, which is described by the (modified) Lorenz equations. The presence of the yield stress significantly alters the dynamics of the system. In particular, the chaotic motion can stop suddenly (sometimes, after a period of chaotic oscillations). Guided by the model equations we performed direct numerical simulations of convection of the Bingham liquid in a square cavity heated from bellow. Our interest has been concentrated on the situation when both buoyancy and plastic forces are large. The obtained results are in a reasonable agreement with the predictions by the Lorenz equations.

  9. A transilient matrix for moist convection

    Energy Technology Data Exchange (ETDEWEB)

    Romps, D.; Kuang, Z.

    2011-08-15

    A method is introduced for diagnosing a transilient matrix for moist convection. This transilient matrix quantifies the nonlocal transport of air by convective eddies: for every height z, it gives the distribution of starting heights z{prime} for the eddies that arrive at z. In a cloud-resolving simulation of deep convection, the transilient matrix shows that two-thirds of the subcloud air convecting into the free troposphere originates from within 100 m of the surface. This finding clarifies which initial height to use when calculating convective available potential energy from soundings of the tropical troposphere.

  10. Assisted Housing - Public Housing Authorities - National Geospatial Data Asset (NGDA)

    Data.gov (United States)

    Department of Housing and Urban Development — Public Housing was established to provide decent and safe rental housing for eligible low-income families, the elderly, and persons with disabilities. Public housing...

  11. Housing and Health: The relationship between housing conditions ...

    African Journals Online (AJOL)

    okanlawon

    2011-10-22

    Oct 22, 2011 ... Housing and Health: The relationship between housing ... The authors in chapter one, deal extensively with historical context of housing and health chronologically ... Housing and Health: Time Again for Public Health Action.

  12. Experimental investigations on the transient behaviour of nuclear heat plants with natural convection

    International Nuclear Information System (INIS)

    Adam, E.; Sydow, J.; Wolff, J.

    1988-01-01

    Apart from the theoretical approach, practical experiments concerning the transient behaviour of the primary loop of reactors with natural coolant convection are necessary in order to evaluate the safety systems of reactors providing heat for industrial and communal consumers. The article presents experiments concerning the transient behaviour of the experimental plant DANTON, which models the reactor AST-500, and gives a preview of further research. (orig.) [de

  13. Inadequate housing in Ghana

    Directory of Open Access Journals (Sweden)

    Franklin Obeng-Odoom

    2011-01-01

    Full Text Available Two themes are evident in housing research in Ghana. One involves the study of how to increase the number of dwellings to correct the overall housing deficit, and the other focuses on how to improve housing for slum dwellers. Between these two extremes, there is relatively little research on why the existing buildings are poorly maintained. This paper is based on a review of existing studies on inadequate housing. It synthesises the evidence on the possible reasons for this neglect, makes a case for better maintenance and analyses possible ways of reversing the problem of inadequate housing.

  14. Moodulmaja Passion House = "Passion House" modular home

    Index Scriptorium Estoniae

    2015-01-01

    Moodulmaja Passion House. Arhitektuuri sihtkapitali innovatsioonipreemia 2013 kvaliteetse disaini ja perspektiivika arendustegevuse oskusliku sidumise eest. Arhitekt Eero Endjärv (Arhitekt11), sisearhitekt Hannelore Kääramees (Arhitekt11)

  15. Housing Data Base for Sustainable Housing Provision

    African Journals Online (AJOL)

    Sultan

    The research employed a mixed method approach by collecting both quantitative and qualitative data which were analysed using descriptive analysis in SPSS. The results are ... critical examination of mass housing design in. Nigeria will show ...

  16. Closing the loop.

    Science.gov (United States)

    Dassau, E; Atlas, E; Phillip, M

    2010-02-01

    The dream of closing the loop is actually the dream of creating an artificial pancreas and freeing the patients from being involved with the care of their own diabetes. Insulin-dependent diabetes (type 1) is a chronic incurable disease which requires constant therapy without the possibility of any 'holidays' or insulin-free days. It means that patients have to inject insulin every day of their life, several times per day, and in order to do it safely they also have to measure their blood glucose levels several times per day. Patients need to plan their meals, their physical activities and their insulin regime - there is only very small room for spontaneous activities. This is why the desire for an artificial pancreas is so strong despite the fact that it will not cure the diabetic patients. Attempts to develop a closed-loop system started in the 1960s but never got to a clinical practical stage of development. In recent years the availability of continuous glucose sensors revived those efforts and stimulated the clinician and researchers to believe that closing the loop might be possible nowadays. Many papers have been published over the years describing several different ideas on how to close the loop. Most of the suggested systems have a sensing arm that measures the blood glucose repeatedly or continuously, an insulin delivery arm that injects insulin upon command and a computer that makes the decisions of when and how much insulin to deliver. The differences between the various published systems in the literature are mainly in their control algorithms. However, there are also differences related to the method and site of glucose measurement and insulin delivery. SC glucose measurements and insulin delivery are the most studied option but other combinations of insulin measurements and glucose delivery including intravascular and intraperitoneal (IP) are explored. We tried to select recent publications that we believe had influenced and inspired people interested

  17. Loop Quantum Cosmology.

    Science.gov (United States)

    Bojowald, Martin

    2008-01-01

    Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time. Supplementary material is available for this article at 10.12942/lrr-2008-4.

  18. Loop Quantum Cosmology

    Directory of Open Access Journals (Sweden)

    Bojowald Martin

    2008-07-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical spacetime inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding spacetime is then modified. One particular theory is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. The main effects are introduced into effective classical equations, which allow one to avoid the interpretational problems of quantum theory. They give rise to new kinds of early-universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function, which allows an extension of quantum spacetime beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of spacetime arising in loop quantum gravity and its application to cosmology sheds light on more general issues, such as the nature of time.

  19. Loop Quantum Cosmology

    Directory of Open Access Journals (Sweden)

    Bojowald Martin

    2005-12-01

    Full Text Available Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical space-time inevitably comes to an end after a finite amount of proper time. This presents a breakdown of the classical picture and requires an extended theory for a meaningful description. Since small length scales and high curvatures are involved, quantum effects must play a role. Not only the singularity itself but also the surrounding space-time is then modified. One particular realization is loop quantum cosmology, an application of loop quantum gravity to homogeneous systems, which removes classical singularities. Its implications can be studied at different levels. Main effects are introduced into effective classical equations which allow to avoid interpretational problems of quantum theory. They give rise to new kinds of early universe phenomenology with applications to inflation and cyclic models. To resolve classical singularities and to understand the structure of geometry around them, the quantum description is necessary. Classical evolution is then replaced by a difference equation for a wave function which allows to extend space-time beyond classical singularities. One main question is how these homogeneous scenarios are related to full loop quantum gravity, which can be dealt with at the level of distributional symmetric states. Finally, the new structure of space-time arising in loop quantum gravity and its application to cosmology sheds new light on more general issues such as time.

  20. Reverse convection in helium and other fluids in the high speed rotating frame: negative and positive buoyancy effects

    International Nuclear Information System (INIS)

    Igra, R.; Scurlock, R.G.; Wu, Y.Y.

    1986-01-01

    Experimental studies of thermo-syphon flows in radial tubes and loops between the axis and the periphery of a rotating helium cryostat have shown that when heat is supplied at an intermediate radius, the heat is carried radially inwards as A flow and radially outwards as B flow. The results with helium suggest that while the steady state patterns of the A and B flows are complex, the heat is divided approximately equally between the conventional A flow and the reverse B flow. A model of convective heating in the rotating frame is presented and two necessary conditions for reverse convection are identified and discussed. The model predicts reverse convection in liquid nitrogen and this is confirmed by experimental measurement. An array of radial ducts is proposed for the cooling of a superconducting AC generator in order to counter the effects of reverse convection in the helium refrigerant

  1. Convective aggregation in realistic convective-scale simulations

    Science.gov (United States)

    Holloway, Christopher E.

    2017-06-01

    To investigate the real-world relevance of idealized-model convective self-aggregation, five 15 day cases of real organized convection in the tropics are simulated. These include multiple simulations of each case to test sensitivities of the convective organization and mean states to interactive radiation, interactive surface fluxes, and evaporation of rain. These simulations are compared to self-aggregation seen in the same model configured to run in idealized radiative-convective equilibrium. Analysis of the budget of the spatial variance of column-integrated frozen moist static energy shows that control runs have significant positive contributions to organization from radiation and negative contributions from surface fluxes and transport, similar to idealized runs once they become aggregated. Despite identical lateral boundary conditions for all experiments in each case, systematic differences in mean column water vapor (CWV), CWV distribution shape, and CWV autocorrelation length scale are found between the different sensitivity runs, particularly for those without interactive radiation, showing that there are at least some similarities in sensitivities to these feedbacks in both idealized and realistic simulations (although the organization of precipitation shows less sensitivity to interactive radiation). The magnitudes and signs of these systematic differences are consistent with a rough equilibrium between (1) equalization due to advection from the lateral boundaries and (2) disaggregation due to the absence of interactive radiation, implying disaggregation rates comparable to those in idealized runs with aggregated initial conditions and noninteractive radiation. This points to a plausible similarity in the way that radiation feedbacks maintain aggregated convection in both idealized simulations and the real world.Plain Language SummaryUnderstanding the processes that lead to the organization of tropical rainstorms is an important challenge for weather

  2. Assisted Housing - Multifamily Properties - Assisted

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Multifamily Housing property portfolio consist primarily of rental housing properties with five or more dwelling units such as apartments or town houses, but...

  3. CRUCIB: an axisymmetric convection code

    International Nuclear Information System (INIS)

    Bertram, L.A.

    1975-03-01

    The CRUCIB code was written in support of an experimental program aimed at measurement of thermal diffusivities of refractory liquids. Precise values of diffusivity are necessary to realistic analysis of reactor safety problems, nuclear waste disposal procedures, and fundamental metal forming processes. The code calculates the axisymmetric transient convective motions produced in a right circular cylindrical crucible, which is surface heated by an annular heat pulse. Emphasis of this report is placed on the input-output options of the CRUCIB code, which are tailored to assess the importance of the convective heat transfer in determining the surface temperature distribution. Use is limited to Prandtl numbers less than unity; larger values can be accommodated by replacement of a single block of the code, if desired. (U.S.)

  4. Fluid convection, constraint and causation

    Science.gov (United States)

    Bishop, Robert C.

    2012-01-01

    Complexity—nonlinear dynamics for my purposes in this essay—is rich with metaphysical and epistemological implications but is receiving sustained philosophical analysis only recently. I will explore some of the subtleties of causation and constraint in Rayleigh–Bénard convection as an example of a complex phenomenon, and extract some lessons for further philosophical reflection on top-down constraint and causation particularly with respect to causal foundationalism. PMID:23386955

  5. Computer simulation of natural circulation in FFTF secondary loops

    International Nuclear Information System (INIS)

    Beaver, T.R.; Turner, D.M.; Additon, S.L.

    1979-07-01

    A thermal/hydraulic model of the FFTF secondary heat transport loop has been calibrated against transient natural circulation test data collected March to May 1979. The tests verified that the transition to natural convective flow could be effected from near isothermal conditions without excessive cooling at the air dump heat exchangers. Key empirical parameters of pressure drop and heat loss were found to be at 88% and 81% of pretest estimates, respectively. Pretest piping thermal transport and flow calculational models required no further revision to produce good agreement with test data

  6. Cryogenic helium gas convection research

    International Nuclear Information System (INIS)

    Donnelly, R.J.

    1994-10-01

    This is a report prepared by a group interested in doing research in thermal convection using the large scale refrigeration facilities available at the SSC Laboratories (SSCL). The group preparing this report consists of Michael McAshan at SSCL, Robert Behringer at Duke University, Katepalli Sreenivasan at Yale University, Xiao-Zhong Wu at Northern Illinois University and Russell Donnelly at the University of Oregon, who served as Editor for this report. This study reports the research and development opportunities in such a project, the technical requirements and feasibility of its construction and operation, and the costs associated with the needed facilities and support activities. The facility will be a unique national resource for studies of high-Reynolds-number and high-Rayleigh-number and high Rayleigh number turbulence phenomena, and is one of the six items determined as suitable for potential funding through a screening of Expressions of Interest. The proposed facility is possible only because of the advanced cryogenic technology available at the SSCL. Typical scientific issues to be addressed in the facility will be discussed. It devolved during our study, that while the main experiment is still considered to be the thermal convection experiment discussed in our original Expression of Interest, there are now a very substantial set of other, important and fundamental experiments which can be done with the large cryostat proposed for the convection experiment. We believe the facility could provide several decades of front-line research in turbulence, and shall describe why this is so

  7. Thermosolutal convection during dendritic solidification

    Science.gov (United States)

    Heinrich, J. C.; Nandapurkar, P.; Poirier, D. R.; Felicelli, S.

    1989-01-01

    This paper presents a mathematical model for directional solidification of a binary alloy including a dendritic region underlying an all-liquid region. It is assumed initially that there exists a nonconvecting state with planar isotherms and isoconcentrates solidifying at a constant velocity. The stability of this system has been analyzed and nonlinear calculations are performed that show the effect of convection in the solidification process when the system is unstable. Results of calculations for various cases defined by the initial temperature gradient at the dendrite tips and varying strength of the gravitational field are presented for systems involving lead-tin alloys. The results show that the systems are stable for a gravitational constant of 0.0001 g(0) and that convection can be suppressed by appropriate choice of the container's size for higher values of the gravitational constant. It is also concluded that for the lead-tin systems considered, convection in the mushy zone is not significant below the upper 20 percent of the dendritic zone, if al all.

  8. LoopIng: a template-based tool for predicting the structure of protein loops.

    KAUST Repository

    Messih, Mario Abdel

    2015-08-06

    Predicting the structure of protein loops is very challenging, mainly because they are not necessarily subject to strong evolutionary pressure. This implies that, unlike the rest of the protein, standard homology modeling techniques are not very effective in modeling their structure. However, loops are often involved in protein function, hence inferring their structure is important for predicting protein structure as well as function.We describe a method, LoopIng, based on the Random Forest automated learning technique, which, given a target loop, selects a structural template for it from a database of loop candidates. Compared to the most recently available methods, LoopIng is able to achieve similar accuracy for short loops (4-10 residues) and significant enhancements for long loops (11-20 residues). The quality of the predictions is robust to errors that unavoidably affect the stem regions when these are modeled. The method returns a confidence score for the predicted template loops and has the advantage of being very fast (on average: 1 min/loop).www.biocomputing.it/loopinganna.tramontano@uniroma1.itSupplementary data are available at Bioinformatics online.

  9. Wilson loops in minimal surfaces

    International Nuclear Information System (INIS)

    Drukker, Nadav; Gross, David J.; Ooguri, Hirosi

    1999-01-01

    The AdS/CFT correspondence suggests that the Wilson loop of the large N gauge theory with N = 4 supersymmetry in 4 dimensions is described by a minimal surface in AdS 5 x S 5 . The authors examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which the authors call BPS loops, whose expectation values are free from ultra-violet divergence. They formulate the loop equation for such loops. To the extent that they have checked, the minimal surface in AdS 5 x S 5 gives a solution of the equation. The authors also discuss the zig-zag symmetry of the loop operator. In the N = 4 gauge theory, they expect the zig-zag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. They will show how this is realized for the minimal surface

  10. Wilson loops and minimal surfaces

    International Nuclear Information System (INIS)

    Drukker, Nadav; Gross, David J.; Ooguri, Hirosi

    1999-01-01

    The AdS-CFT correspondence suggests that the Wilson loop of the large N gauge theory with N=4 supersymmetry in four dimensions is described by a minimal surface in AdS 5 xS 5 . We examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which we call BPS loops, whose expectation values are free from ultraviolet divergence. We formulate the loop equation for such loops. To the extent that we have checked, the minimal surface in AdS 5 xS 5 gives a solution of the equation. We also discuss the zigzag symmetry of the loop operator. In the N=4 gauge theory, we expect the zigzag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. We will show how this is realized for the minimal surface. (c) 1999 The American Physical Society

  11. Radon in Syrian houses

    International Nuclear Information System (INIS)

    Othman, I.; Hushari, M.; Raja, G.; Alsawaf, A.

    1996-01-01

    A nationwide investigation of radon levels in Syrian houses was carried out during the period 1991-1993. Passive radon diffusion dosemeters using polycarbonate detectors were distributed in houses all over Syria. Detectors were subjected to electrochemical etching to reveal latent tracks of alpha particles. The mean radon concentration in Syrian houses was found to be 45 Bq m -3 with some values several times higher. This investigation indicated that there were a few houses in Syria that require remedial action. Most houses that have high levels of radon were found in the southern area, especially in the Damascus governorate. The study also indicated that radon concentrations were higher in old houses built from mud with no tiling. (author)

  12. On some properties of conjugacy closed loops

    International Nuclear Information System (INIS)

    Adeniran, John Olusola

    2002-07-01

    It is shown that central loops are not conjugacy closed loops but instead are loops of units in their loop algebras that are conjugacy closed. It is also shown that certain inner mappings of a conjugacy closed loop are nuclear. Some invariants of left conjugacy closed loops are obtained. (author)

  13. 75 FR 4100 - Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing...

    Science.gov (United States)

    2010-01-26

    ... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5376-N-01] Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing Marketing (AFHM) Plan-Single Family Housing and Affirmative Fair Housing Marketing (AFHM) Plan- Cooperatives/Condominiums AGENCY: Office of...

  14. Specialists' meeting on evaluation of decay heat removal by natural convection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-02-01

    Decay heat removal by natural convection (DHRNC) is essential to enhancing the safety of liquid metal fast reactors (LMFRs). Various design concepts related to DHRNC have been proposed and experimental and analytical studies have been carried out in a number of countries. The purpose of this Specialists' Meeting on 'Decay Heat Removal by Natural Convection' organized by the International Working Group on Fast Reactors IAEA, is to exchange information about the state of the art related to methodologies on evaluation of DHRNC features (experimental studies and code developments) and to discuss problems which need to be solved in order to evaluate DHRNC properly and reasonably. The following main topical areas were discussed by delegates: Overview; Experimental studies and code validation; Design study. Two main DHR systems for LMFR are under consideration: (i) direct reactor auxiliary cooling system (DRACS) with immersed DFIX in main vessel, intermediate sodium loop and sodium-air heat exchanger; and (ii) auxiliary cooling system which removes heat from the outside surface of the reactor vessel by natural convection of air (RVACS). The practicality and economic viability of the use of RVACS is possible up to a modular type reactor or a middle size reactor based on current technology. For the large monolithic plant concepts DRACS is preferable. The existing experimental results and the codes show encouraging results so that the decay heat removal by pure natural convection is feasible. Concerning the objective, 'passive safety', the DHR by pure natural convection is essential feature to enhance the reliability of DHR.

  15. Specialists' meeting on evaluation of decay heat removal by natural convection

    International Nuclear Information System (INIS)

    1993-02-01

    Decay heat removal by natural convection (DHRNC) is essential to enhancing the safety of liquid metal fast reactors (LMFRs). Various design concepts related to DHRNC have been proposed and experimental and analytical studies have been carried out in a number of countries. The purpose of this Specialists' Meeting on 'Decay Heat Removal by Natural Convection' organized by the International Working Group on Fast Reactors IAEA, is to exchange information about the state of the art related to methodologies on evaluation of DHRNC features (experimental studies and code developments) and to discuss problems which need to be solved in order to evaluate DHRNC properly and reasonably. The following main topical areas were discussed by delegates: Overview; Experimental studies and code validation; Design study. Two main DHR systems for LMFR are under consideration: (i) direct reactor auxiliary cooling system (DRACS) with immersed DFIX in main vessel, intermediate sodium loop and sodium-air heat exchanger; and (ii) auxiliary cooling system which removes heat from the outside surface of the reactor vessel by natural convection of air (RVACS). The practicality and economic viability of the use of RVACS is possible up to a modular type reactor or a middle size reactor based on current technology. For the large monolithic plant concepts DRACS is preferable. The existing experimental results and the codes show encouraging results so that the decay heat removal by pure natural convection is feasible. Concerning the objective, 'passive safety', the DHR by pure natural convection is essential feature to enhance the reliability of DHR

  16. The Housing Finance Revolution

    OpenAIRE

    Richard K. Green; Susan M. Wachter

    2007-01-01

    While other countries dismantled their segmented housing finance systems and linked housing finance to capital markets through deregulated depositories, the US linked housing finance to capital markets through depository deregulation and securitization. Elsewhere securitization has not developed. The US provided the underpinnings for its mortgage security infrastructure with the creation of FNMA in 1938 and in order to create liquidity in the mortgage market required the standardization of mo...

  17. The architects house

    DEFF Research Database (Denmark)

    Welling, Helen

    2007-01-01

    The architects house is an article on Edward Heiberg's own house built in 1924. Edward Heiberg was a strong advocate of functionalism, and of the notion that hitherto individualistic and emotional architecture should be replaced by an objective function-based architecture with dwellings...... for everyone. In 1924 he designed a house for himself and his family: one of the first examples of functionalism in Denmark....

  18. Convective overshoot at the solar tachocline

    Science.gov (United States)

    Brown, Benjamin; Oishi, Jeffrey S.; Anders, Evan H.; Lecoanet, Daniel; Burns, Keaton; Vasil, Geoffrey M.

    2017-08-01

    At the base of the solar convection zone lies the solar tachocline. This internal interface is where motions from the unstable convection zone above overshoot and penetrate downward into the stiffly stable radiative zone below, driving gravity waves, mixing, and possibly pumping and storing magnetic fields. Here we study the dynamics of convective overshoot across very stiff interfaces with some properties similar to the internal boundary layer within the Sun. We use the Dedalus pseudospectral framework and study fully compressible dynamics at moderate to high Peclet number and low Mach number, probing a regime where turbulent transport is important, and where the compressible dynamics are similar to those of convective motions in the deep solar interior. We find that the depth of convective overshoot is well described by a simple buoyancy equilibration model, and we consider implications for dynamics at the solar tachocline and for the storage of magnetic fields there by overshooting convection.

  19. The convection electric field in auroral substorms

    DEFF Research Database (Denmark)

    Gjerløv, Jesper Wittendorff; Hoffman, R.A.

    2001-01-01

    Dynamics Explorer 2 (DE 2) electric field and ion drift data are used in a statistical study of the ionospheric convection electric field in bulge-type auroral substorms. Thirty-one individual DE 2 substorm crossings were carefully selected and organized by the use of global auroral images obtained...... this database enabled us to compile a model of the ionospheric convection electric field. The characteristics of the premidnight convection reversal show a pronounced local time dependency. Far west of the surge it is a fairly well defined point reversal or convection shear. Approaching the surge and within...... the surge it is a region of weak electric fields increasing in width toward midnight that separates regions of equatorward and poleward electric fields. Therefore we adopt the term Harang region rather than the Harang discontinuity for the premidnight convection reversal. A relatively narrow convection...

  20. The pattern of convection in the Sun

    International Nuclear Information System (INIS)

    Weiss, N.O.

    1976-01-01

    The structure of solar magnetic fields is dominated by the effects of convection, which should be incorporated in any model of the solar cycle. Although mixing length theory is adequate for calculating the structure of main sequence stars, a better description of convection is needed for any detailed dynamo model. Recent work on nonlinear convection at low Prandt numbers is reviewed. There has been some progress towards a theory of compressible convection, though there is still no firm theoretical evidence for cells with scales less than the depth of the convecting layer. However, it remains likely that the pattern of solar convection is dominated by granules, supergranules and giant cells. The effects of rotation on these cells are briefly considered. (Auth.)

  1. Response of the primary piping loop to an HCDA

    International Nuclear Information System (INIS)

    Chang, Y.W.; Moneim, M.T.A.; Wang, C.Y.; Gvildys, J.

    1975-01-01

    The paper describes a method for analyzing the response of the primary piping loop that consists of straight pipes, elbows, and other components connected in series and subject to hypothetical core disruptive accident (HCDA) loads at both ends of the loop. The complete hydrodynamic equations in two-dimensions, that include both the nonlinear convective and viscous dissipation terms are used for the fluid dynamics together with the implicit ICE technique. The external walls of the pipes and components are treated as thin shells in which the analysis accounts for the membrane and bending strength of the wall, elastic-plastic material behavior, as well as large deformation under the effect of transient loading conditions. In the straight pipes, the flow is assumed to be axisymmetric; in the elbow regions, the two dimensions considered are the r and theta directions. The flow in the other components is also assumed to be axisymmetric; the components are modeled as a circular cylinder, in which the radius of the cylinder can be varied to conform with the outside shape of the component and the flow area inside can be changed independently from the outside shape. However, they must remain axially symmetric. The method is applied to a piping loop which consists of six elastic-plastic pipes and five rigid elbows connected in series and subjected to pressure pulses at both ends of the loop

  2. Two-loop polygon Wilson loops in N = 4 SYM

    International Nuclear Information System (INIS)

    Anastasiou, C.; Brandhuber, A.; Heslop, P.; Spence, B.; Travaglini, G.; Khoze, V.V.

    2009-01-01

    We compute for the first time the two-loop corrections to arbitrary n-gon lightlike Wilson loops in N = 4 supersymmetric Yang-Mills theory, using efficient numerical methods. The calculation is motivated by the remarkable agreement between the finite part of planar six-point MHV amplitudes and hexagon Wilson loops which has been observed at two loops. At n = 6 we confirm that the ABDK/BDS ansatz must be corrected by adding a remainder function, which depends only on conformally invariant ratios of kinematic variables. We numerically compute remainder functions for n = 7,8 and verify dual conformal invariance. Furthermore, we study simple and multiple collinear limits of the Wilson loop remainder functions and demonstrate that they have precisely the form required by the collinear factorisation of the corresponding two-loop n-point amplitudes. The number of distinct diagram topologies contributing to the n-gon Wilson loops does not increase with n, and there is a fixed number of 'master integrals', which we have computed. Thus we have essentially computed general polygon Wilson loops, and if the correspondence with amplitudes continues to hold, all planar n-point two-loop MHV amplitudes in the N = 4 theory.

  3. High temperature storage loop :

    Energy Technology Data Exchange (ETDEWEB)

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  4. Accelerating the loop expansion

    International Nuclear Information System (INIS)

    Ingermanson, R.

    1986-01-01

    This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi 4 theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs

  5. A complex approach to the blue-loop problem

    Science.gov (United States)

    Ostrowski, Jakub; Daszynska-Daszkiewicz, Jadwiga

    2015-08-01

    The problem of the blue loops during the core helium burning, outstanding for almost fifty years, is one of the most difficult and poorly understood problems in stellar astrophysics. Most of the work focused on the blue loops done so far has been performed with old stellar evolution codes and with limited computational resources. In the end the obtained conclusions were based on a small sample of models and could not have taken into account more advanced effects and interactions between them.The emergence of the blue loops depends on many details of the evolution calculations, in particular on chemical composition, opacity, mixing processes etc. The non-linear interactions between these factors contribute to the statement that in most cases it is hard to predict without a precise stellar modeling whether a loop will emerge or not. The high sensitivity of the blue loops to even small changes of the internal structure of a star yields one more issue: a sensitivity to numerical problems, which are common in calculations of stellar models on advanced stages of the evolution.To tackle this problem we used a modern stellar evolution code MESA. We calculated a large grid of evolutionary tracks (about 8000 models) with masses in the range of 3.0 - 25.0 solar masses from the zero age main sequence to the depletion of helium in the core. In order to make a comparative analysis, we varied metallicity, helium abundance and different mixing parameters resulting from convective overshooting, rotation etc.The better understanding of the properties of the blue loops is crucial for our knowledge of the population of blue supergiants or pulsating variables such as Cepheids, α-Cygni or Slowly Pulsating B-type supergiants. In case of more massive models it is also of great importance for studies of the progenitors of supernovae.

  6. Titan Balloon Convection Model, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovative research effort is directed at determining, quantitatively, the convective heat transfer coefficients applicable to a Montgolfiere balloon operating...

  7. REVERSALS IN THE 6-CELLS CONVECTION DRIVEN

    Directory of Open Access Journals (Sweden)

    G.M. Vodinchar

    2015-12-01

    Full Text Available We describe the large-scale model geodynamo, which based on indirect data of inhomogeneities in the density of the Earth’s core. Convection structure is associated with spherical harmonic Y24 , which defines the basic poloidal component of velocity. Coriolis drift of this mode determines the toroidal component of velocity. Thus, 6 convective cells are formed. The model takes into account the feedback effect of the magnetic field on convection. It was ascertained that the model contains stable regimes of field generation. The velocity of convection and the dipole component of the magnetic field are close to the observed ones.

  8. Scale analysis of convective clouds

    Directory of Open Access Journals (Sweden)

    Micha Gryschka

    2008-12-01

    Full Text Available The size distribution of cumulus clouds due to shallow and deep convection is analyzed using satellite pictures, LES model results and data from the German rain radar network. The size distributions found can be described by simple power laws as has also been proposed for other cloud data in the literature. As the observed precipitation at ground stations is finally determined by cloud numbers in an area and individual sizes and rain rates of single clouds, the cloud size distributions might be used for developing empirical precipitation forecasts or for validating results from cloud resolving models being introduced to routine weather forecasts.

  9. Characterizing Convection in Stellar Atmospheres

    International Nuclear Information System (INIS)

    Tanner, Joel; Basu, Sarbani; Demarque, Pierre; Robinson, Frank

    2011-01-01

    We perform 3D radiative hydrodynamic simulations to study the properties of convection in the superadiabatic layer of stars. The simulations show differences in both the stratification and turbulent quantities for different types of stars. We extract turbulent pressure and eddy sizes, as well as the T-τ relation for different stars and find that they are sensitive to the energy flux and gravity. We also show that contrary to what is usually assumed in the field of stellar atmospheres, the structure and gas dynamics of simulations of turbulent atmospheres cannot be parameterized with T eff and log(g) alone.

  10. Mirror symmetry and loop operators

    Energy Technology Data Exchange (ETDEWEB)

    Assel, Benjamin [Department of Mathematics, King’s College London,The Strand, London WC2R 2LS (United Kingdom); Gomis, Jaume [Perimeter Institute for Theoretical Physics,Waterloo, Ontario, N2L 2Y5 (Canada)

    2015-11-09

    Wilson loops in gauge theories pose a fundamental challenge for dualities. Wilson loops are labeled by a representation of the gauge group and should map under duality to loop operators labeled by the same data, yet generically, dual theories have completely different gauge groups. In this paper we resolve this conundrum for three dimensional mirror symmetry. We show that Wilson loops are exchanged under mirror symmetry with Vortex loop operators, whose microscopic definition in terms of a supersymmetric quantum mechanics coupled to the theory encode in a non-trivial way a representation of the original gauge group, despite that the gauge groups of mirror theories can be radically different. Our predictions for the mirror map, which we derive guided by branes in string theory, are confirmed by the computation of the exact expectation value of Wilson and Vortex loop operators on the three-sphere.

  11. Reactor recirculation pump test loop

    International Nuclear Information System (INIS)

    Taka, Shusei; Kato, Hiroyuki

    1979-01-01

    A test loop for a reactor primary loop recirculation pumps (PLR pumps) has been constructed at Ebara's Haneda Plant in preparation for production of PLR pumps under license from Byron Jackson Pump Division of Borg-Warner Corporation. This loop can simulate operating conditions for test PLR pumps with 130 per cent of the capacity of pumps for a 1100 MWe BWR plant. A main loop, primary cooling system, water demineralizer, secondary cooling system, instrumentation and control equipment and an electric power supply system make up the test loop. This article describes the test loop itself and test results of two PLR pumps for Fukushima No. 2 N.P.S. Unit 1 and one main circulation pump for HAZ Demonstration Test Facility. (author)

  12. Housing Survey. Campus Housing: Finding the Balance

    Science.gov (United States)

    O'Connor, Shannon

    2016-01-01

    Depending on where you look for statistics, the number of students enrolling in colleges or universities is increasing, decreasing or remaining the about the same. Regardless of those trends, campus housing is a marketing tool for institutions looking to draw students to and keep them on campus. Schools need to offer sufficient beds and…

  13. A Painted House In Ankara: Dedebayrak House

    Directory of Open Access Journals (Sweden)

    Muzaffer Karaaslan

    2016-06-01

    Full Text Available The conservative family lifestyle in the Ottoman State affected the ways that houses were planned and decorated. Different decorative programs emerged with major differences in each period. New techniques and styles began to be seen in the 18th century thanks to the influence of the West. This article will focus on the decoration of Dedebayrak House in Ankara. Decoration in the architecture found within the boundaries of Ankara consist mostly of geometrical or floral decorations and various inscriptions. The Dedebayrak House not only has these kind of decorations, but also it has these decorations in its architectural descriptions, so it makes this house the only one to have survived in Ankara. Moreover, this building is especially important as the décor included work belonging to Nakkaş Mustafa. However, these decorative features do not remain today. The situation in Turkey is such that architecture is not conserved, which leads to many historically important buildings vanishing. Neither local authorities, nor the owner of these buildings look after these buildings properly, leading their specific historical features to be lost. This situation both damages the urban fabric and harms the historical heritage of the city. Therefore, decorative features in the building will be analysed both on their own and compared to other buildings in Ankara in order to create an overall picture.

  14. Dream house in Australia

    DEFF Research Database (Denmark)

    Andersen, Michael Asgaard

    2004-01-01

    This first book in the Utzon Library, which deals with Utzon's own houses, contains a number of drawings that have not previously been published. This is especially true of the four projects for his house in Bayview, Sydney, which unfortunately never got past the drawing stage, as Utzon had left ...

  15. Radon house doctor

    International Nuclear Information System (INIS)

    Nitschke, I.A.; Brennan, T.; Wadach, J.B.; O'Neil, R.

    1986-01-01

    The term house doctor may be generalized to include persons skilled in the use of instruments and procedures necessary to identify, diagnose, and correct indoor air quality problems as well as energy, infiltration, and structural problems in houses. A radon house doctor would then be a specialist in radon house problems. Valuable experience in the skills necessary to be developed by radon house doctors has recently been gained in an extensive radon monitoring and mitigation program in upstate New York sponsored by Niagara Mohawk Power Corporation and the New York State Energy Research and Development Authority. These skills, to be described in detail in this paper, include: (i) the use of appropriate instruments, (ii) the evaluation of the symptoms of a radon-sick house, (iii) the diagnostic procedures required to characterize radon sources in houses, (iv) the prescription procedures needed to specify treatment of the problem, (v) the supervision of the implementation of the treatment program, (vi) the check-up procedures required to insure the house cured of radon problems. 31 references, 3 tables

  16. Housing consumption and urbanization

    OpenAIRE

    Lozano-Gracia, Nancy; Young, Cheryl

    2014-01-01

    Rapid urbanization in Sub-Saharan Africa places immense pressure on urban services to meet the needs of the burgeoning urban population. Although several country- or city-level reports offer insight into the housing challenges of specific places, little is known about regional patterns affecting housing markets. This lack of clear knowledge on the relative importance of the factors influen...

  17. House of tomorrow today

    NARCIS (Netherlands)

    Lichtenberg, J.J.N.; Ham, M.; Hensen, J.L.M.

    2011-01-01

    The House of Tomorrow Today is a project focussing on a healthy, energy producing dwelling to be realized with today¿s proven technology. The project aims at an energy plus level based on the principles as formulated in SmartBuilding (Slimbouwen) [1] ActiveHouse [2] and HoTT [3] It can be seen as

  18. The Index House

    International Nuclear Information System (INIS)

    Reilly, M.A.

    1990-01-01

    This paper reports on the Pennsylvania Radon Research and Demonstration Project. The project involved the monitoring of the Index House for indoor radon, and was one of the earliest programs involving indoor radon contamination. The history of the house, the investigation, and testing and remediation procedures are discussed

  19. Multiple pump housing

    Science.gov (United States)

    Donoho, II, Michael R.; Elliott; Christopher M.

    2010-03-23

    A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

  20. Ndebele Inspired Houses

    Science.gov (United States)

    Rice, Nicole

    2012-01-01

    The house paintings of the South African Ndebele people are more than just an attempt to improve the aesthetics of a community; they are a source of identity and significance for Ndebele women. In this article, the author describes an art project wherein students use the tradition of Ndebele house painting as inspiration for creating their own…

  1. Loop Heat Pipe Startup Behaviors

    Science.gov (United States)

    Ku, Jentung

    2016-01-01

    A loop heat pipe must start successfully before it can commence its service. The startup transient represents one of the most complex phenomena in the loop heat pipe operation. This paper discusses various aspects of loop heat pipe startup behaviors. Topics include the four startup scenarios, the initial fluid distribution between the evaporator and reservoir that determines the startup scenario, factors that affect the fluid distribution between the evaporator and reservoir, difficulties encountered during the low power startup, and methods to enhance the startup success. Also addressed are the pressure spike and pressure surge during the startup transient, and repeated cycles of loop startup and shutdown under certain conditions.

  2. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    Baity, F.W.

    1987-01-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak

  3. Onset of Vibrational Convection in a Binary Fluid Saturated Non-Darcy Porous Layer Heated from Above

    Directory of Open Access Journals (Sweden)

    Saravanan S.

    2012-07-01

    Full Text Available A linear stability analysis is used to investigate the influence of mechanical vibration on the onset of thermosolutal convection in a horizontal porous layer heated and salted from above. Vibrations are considered with arbitrary amplitude and frequency. The Brinkman extended Darcy model is used to describe the flow and the Oberbeck-Boussinesq approximation is employed. Continued fraction method and Floquet theory are used to determine the convective instability threshold. It is found that the solutal Rayleigh number has the stabilizing effect. The existence of a closed disconnected loop of synchronous mode is predicted in the marginal curve for moderate values of solutal Rayleigh number and vibration amplitude.

  4. The Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, Tina; Slaug, Bjørn; Brandt, Åse

    2010-01-01

    This study addresses development of a content valid cross-Nordic version of the Housing Enabler and investigation of its inter-rater reliability when used in occupational therapy rating situations, involving occupational therapists, clients and their home environments. The instrument was translated...... from the original Swedish version of the Housing Enabler, and adapted according to accessibility norms and guidelines for housing design in Sweden, Denmark, Finland and Iceland. This iterative process involved occupational therapists, architects, building engineers and professional translators......, resulting in the Nordic Housing Enabler. For reliability testing, the sampling strategy and data collection procedures used were the same in all countries. Twenty voluntary occupational therapists, pair-wise but independently from each other, collected data from 106 cases by means of the Nordic Housing...

  5. Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, Tina; Brandt, Åse

    Development and reliability testing of the Nordic Housing Enabler – an instrument for accessibility assessment of the physical housing. Tina Helle & Åse Brandt University of Lund, Health Sciences, Faculty of Medicine (SE) and University College Northern Jutland, Occupational Therapy department (DK......). Danish Centre for Assistive Technology. Abstract. For decades, accessibility to the physical housing environment for people with functional limitations has been of interest politically, professionally and for the users. Guidelines and norms on accessible housing design have gradually been developed......, however, the built environment shows serious deficits when it comes to accessibility. This study addresses development of a content valid cross-Nordic version of the Housing Enabler and investigation of inter-rater reliability, when used in occupational therapy practice. The instrument was translated from...

  6. Situation based housing

    DEFF Research Database (Denmark)

    Duelund Mortensen, Peder; Welling, Helen; Wiell Nordberg, Lene

    2007-01-01

    of the average family's lifestyle. These dwellings were ground-breaking when they were built, but today are clearly a product of their time. The reaction to functionalism and the postwar mass production gave rise to flexible dwelling with countless possibilities for room division. The housing of this period has...... characteristics which in the long run have proven to be unfortunate both in terms in terms of durability and architectural quality. Today there is a focus on the development of more open and functionally non-determined housing. A number of new housing schemes in and around Copenhagen reveal a variety...... of approaches to these goals. This working paper reviews not only a selection of new housing types, but also dwellings from the past, which each contain an aspect of changeability. Our study is based on information from users in the selected housing schemes, gathered from questionnaires, information about...

  7. Two-dimensional turbulent convection

    Science.gov (United States)

    Mazzino, Andrea

    2017-11-01

    We present an overview of the most relevant, and sometimes contrasting, theoretical approaches to Rayleigh-Taylor and mean-gradient-forced Rayleigh-Bénard two-dimensional turbulence together with numerical and experimental evidences for their support. The main aim of this overview is to emphasize that, despite the different character of these two systems, especially in relation to their steadiness/unsteadiness, turbulent fluctuations are well described by the same scaling relationships originated from the Bolgiano balance. The latter states that inertial terms and buoyancy terms balance at small scales giving rise to an inverse kinetic energy cascade. The main difference with respect to the inverse energy cascade in hydrodynamic turbulence [R. H. Kraichnan, "Inertial ranges in two-dimensional turbulence," Phys. Fluids 10, 1417 (1967)] is that the rate of cascade of kinetic energy here is not constant along the inertial range of scales. Thanks to the absence of physical boundaries, the two systems here investigated turned out to be a natural physical realization of the Kraichnan scaling regime hitherto associated with the elusive "ultimate state of thermal convection" [R. H. Kraichnan, "Turbulent thermal convection at arbitrary Prandtl number," Phys. Fluids 5, 1374-1389 (1962)].

  8. Vortex loops and Majoranas

    International Nuclear Information System (INIS)

    Chesi, Stefano; Jaffe, Arthur; Loss, Daniel; Pedrocchi, Fabio L.

    2013-01-01

    We investigate the role that vortex loops play in characterizing eigenstates of interacting Majoranas. We give some general results and then focus on ladder Hamiltonian examples as a test of further ideas. Two methods yield exact results: (i) A mapping of certain spin Hamiltonians to quartic interactions of Majoranas shows that the spectra of these two examples coincide. (ii) In cases with reflection-symmetric Hamiltonians, we use reflection positivity for Majoranas to characterize vortices in the ground states. Two additional methods suggest wider applicability of these results: (iii) Numerical evidence suggests similar behavior for certain systems without reflection symmetry. (iv) A perturbative analysis also suggests similar behavior without the assumption of reflection symmetry

  9. Inductance loop and partial

    CERN Document Server

    Paul, Clayton R

    2010-01-01

    "Inductance is an unprecedented text, thoroughly discussing "loop" inductance as well as the increasingly important "partial" inductance. These concepts and their proper calculation are crucial in designing modern high-speed digital systems. World-renowned leader in electromagnetics Clayton Paul provides the knowledge and tools necessary to understand and calculate inductance." "With the present and increasing emphasis on high-speed digital systems and high-frequency analog systems, it is imperative that system designers develop an intimate understanding of the concepts and methods in this book. Inductance is a much-needed textbook designed for senior and graduate-level engineering students, as well as a hands-on guide for working engineers and professionals engaged in the design of high-speed digital and high-frequency analog systems."--Jacket.

  10. Dynamic PID loop control

    International Nuclear Information System (INIS)

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.

    2011-01-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  11. Uranyl Nitrate Flow Loop

    International Nuclear Information System (INIS)

    Ladd-Lively, Jennifer L

    2008-01-01

    The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO 2 ), uranium tetrafluoride (UF 4 ), and uranium hexafluoride (UF 6 )] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF 6 product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study was sponsored by

  12. Loop Quantum Gravity.

    Science.gov (United States)

    Rovelli, Carlo

    2008-01-01

    The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime , is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i) The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii) A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler's "spacetime foam" intuition. (iii) Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv) A derivation of the Bekenstein-Hawking black-hole entropy. (v) Low-energy calculations, yielding n -point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.

  13. Loop Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Rovelli Carlo

    2008-07-01

    Full Text Available The problem of describing the quantum behavior of gravity, and thus understanding quantum spacetime, is still open. Loop quantum gravity is a well-developed approach to this problem. It is a mathematically well-defined background-independent quantization of general relativity, with its conventional matter couplings. Today research in loop quantum gravity forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained so far are: (i The computation of the spectra of geometrical quantities such as area and volume, which yield tentative quantitative predictions for Planck-scale physics. (ii A physical picture of the microstructure of quantum spacetime, characterized by Planck-scale discreteness. Discreteness emerges as a standard quantum effect from the discrete spectra, and provides a mathematical realization of Wheeler’s “spacetime foam” intuition. (iii Control of spacetime singularities, such as those in the interior of black holes and the cosmological one. This, in particular, has opened up the possibility of a theoretical investigation into the very early universe and the spacetime regions beyond the Big Bang. (iv A derivation of the Bekenstein–Hawking black-hole entropy. (v Low-energy calculations, yielding n-point functions well defined in a background-independent context. The theory is at the roots of, or strictly related to, a number of formalisms that have been developed for describing background-independent quantum field theory, such as spin foams, group field theory, causal spin networks, and others. I give here a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.

  14. Assisted Housing - Public Housing Developments - National Geospatial Data Asset (NGDA)

    Data.gov (United States)

    Department of Housing and Urban Development — The general location of an entire Public Housing Development. A distinct address is chosen to represent the general location of an entire Public Housing Development,...

  15. Benard convection in gaps and cavities

    International Nuclear Information System (INIS)

    Mueller, U.

    1981-04-01

    The article contains two parts. In the first part a condensed review of the most striking phenomena in Benard convection in laterally confined fluid layers is given. In the second part recent experimental and theoretical work on Benard convection in gaps is presented an analysed. (orig.) [de

  16. Convective mixing and accretion in white dwarfs

    International Nuclear Information System (INIS)

    Koester, D.

    1976-01-01

    The evolution of convection zones in cooling white dwarfs with helium envelopes and outer hydrogen layers is calculated with a complete stellar evolution code. It is shown that white dwarfs of spectral type DB cannot be formed from DA stars by convective mixing. However, for cooler temperatures (Tsub(e) [de

  17. Housing And Mounting Structure

    Science.gov (United States)

    Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R.F.; Bryan, Robert P.; Carson, Richard F.; Duckett, III, Edwin B.; McCormick, Frederick B.; Miller, Gregory V.; Peterson, David W.; Smith, Terrance T.

    2005-03-08

    This invention relates to an optical transmitter, receiver or transceiver module, and more particularly, to an apparatus for connecting a first optical connector to a second optical connector. The apparatus comprises: (1) a housing having at least a first end and at least a second end, the first end of the housing capable of receiving the first optical connector, and the second end of the housing capable of receiving the second optical connector; (2) a longitudinal cavity extending from the first end of the housing to the second end of the housing; and (3) an electromagnetic shield comprising at least a portion of the housing. This invention also relates to an apparatus for housing a flexible printed circuit board, and this apparatus comprises: (1) a mounting structure having at least a first surface and a second surface; (2) alignment ridges along the first and second surfaces of the mounting structure, the alignment ridges functioning to align and secure a flexible printed circuit board that is wrapped around and attached to the first and second surfaces of the mounting structure; and (3) a series of heat sink ridges adapted to the mounting structure, the heat sink ridges functioning to dissipate heat that is generated from the flexible printed circuit board.

  18. Southern Ocean Convection and tropical telleconnections

    Science.gov (United States)

    Marinov, I.; Cabre, A.; Gnanadesikan, A.

    2014-12-01

    We show that Southern Ocean (SO) temperatures in the latest generation of Earth System Models exhibit two major modes of variation, one driven by deep convection, the other by tropical variability. We perform a CMIP5 model intercomparison to understand why different climate models represent SO variability so differently in long, control simulations. We show that multiyear variability in Southern Ocean sea surface temperatures (SSTs) can in turn influence oceanic and atmospheric conditions in the tropics on short (atmospheric) time-scales. We argue that the strength and pattern of SO-tropical teleconnections depends on the intensity of SO deep convection. Periodic convection in the SO is a feature of most CMIP5 models under preindustrial forcing (deLavergne et al., 2014). Models show a wide distribution in the spatial extent, periodicity and intensity of their SO convection, with some models convecting most of the time, and some showing very little convection. In a highly convective coupled model, we find that multidecadal variability in SO and global SSTs, as well as SO heat storage are driven by Weddell Sea convective variability, with convective decades relatively warm due to the heat released from the deep southern ocean and non-convective decades cold due to the subsurface storage of heat. Furthermore, pulses of SO convection drive SST and sea ice variations, influencing absorbed shortwave and emitted longwave radiation, wind, cloud and precipitation patterns, with climatic implications for the low latitudes via fast atmospheric teleconnections. We suggest that these high-low latitude teleconnection mechanisms are relevant for understanding hiatus decades. Additionally, Southern Ocean deep convection varied significantly during past, natural climate changes such as during the last deglaciation. Weddell Sea open convection was recently weakened, likely as a consequence of anthropogenic forcing and the resulting surface freshening. Our study opens up the

  19. Transient analysis of house load operation for LNPP

    International Nuclear Information System (INIS)

    Shi Junying; Zheng Bin

    2000-01-01

    The author analysis the transient of house load operation for Ling'ao Nuclear Power Plant by using the methods of dynamic simulation and closed loops of primary and secondary system. The transient of house load operation from 100% FP is the most severe that can occur on the unit in normal operation because it causes immediately shedding of 95% of turbine load and requires the unit to operate steadily at reduced power. The results show that the transient can be successful both at beginning of core life and manual house load operation. However, more attentions must be paid to automatic house load operation caused by grid fault at toward end of core life because the success of the transient could be threatened by the actuation of the protection of high flux and high flux rate

  20. A totally diverting loop colostomy.

    Science.gov (United States)

    Merrett, N. D.; Gartell, P. C.

    1993-01-01

    A technique is described where the distal limb of a loop colostomy is tied with nylon or polydioxanone. This ensures total faecal diversion and dispenses with the supporting rod, enabling early application of stoma appliances. The technique does not interfere with the traditional transverse closure of a loop colostomy. PMID:8379632

  1. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    This thesis deals with topology optimisation for coupled convection problems. The aim is to extend and apply topology optimisation to steady-state conjugate heat transfer problems, where the heat conduction equation governs the heat transfer in a solid and is coupled to thermal transport...... in a surrounding uid, governed by a convection-diffusion equation, where the convective velocity field is found from solving the isothermal incompressible steady-state Navier-Stokes equations. Topology optimisation is also applied to steady-state natural convection problems. The modelling is done using stabilised...... finite elements, the formulation and implementation of which was done partly during a special course as prepatory work for this thesis. The formulation is extended with a Brinkman friction term in order to facilitate the topology optimisation of fluid flow and convective cooling problems. The derived...

  2. Convective penetration in a young sun

    Science.gov (United States)

    Pratt, Jane; Baraffe, Isabelle; Goffrey, Tom; MUSIC developers group

    2018-01-01

    To interpret the high-quality data produced from recent space-missions it is necessary to study convection under realistic stellar conditions. We describe the multi-dimensional, time implicit, fully compressible, hydrodynamic, implicit large eddy simulation code MUSIC. We use MUSIC to study convection during an early stage in the evolution of our sun where the convection zone covers approximately half of the solar radius. This model of the young sun possesses a realistic stratification in density, temperature, and luminosity. We approach convection in a stellar context using extreme value theory and derive a new model for convective penetration, targeted for one-dimensional stellar evolution calculations. This model provides a scenario that can explain the observed lithium abundance in the sun and in solar-like stars at a range of ages.

  3. Numerical simulations of convectively excited gravity waves

    International Nuclear Information System (INIS)

    Glatzmaier, G.A.

    1983-01-01

    Magneto-convection and gravity waves are numerically simulated with a nonlinear, three-dimensional, time-dependent model of a stratified, rotating, spherical fluid shell heated from below. A Solar-like reference state is specified while global velocity, magnetic field, and thermodynamic perturbations are computed from the anelastic magnetohydrodynamic equations. Convective overshooting from the upper (superadiabatic) part of the shell excites gravity waves in the lower (subadiabatic) part. Due to differential rotation and Coriolis forces, convective cell patterns propagate eastward with a latitudinally dependent phase velocity. The structure of the excited wave motions in the stable region is more time-dependent than that of the convective motions above. The magnetic field tends to be concentrated over giant-cell downdrafts in the convective zone but is affected very little by the wave motion in the stable region

  4. Housing Affordability Data System (HADS)

    Data.gov (United States)

    Department of Housing and Urban Development — The Housing Affordability Data System (HADS) is a set of files derived from the 1985 and later national American Housing Survey (AHS) and the 2002 and later Metro...

  5. American Housing Survey (AHS) 2011

    Data.gov (United States)

    Department of Housing and Urban Development — The AHS is the largest, regular national housing sample survey in the United States. The U.S. Census Bureau conducts the AHS to obtain up-to-date housing statistics...

  6. EURISOL-DS METEX: Cooling and Temperature Control of the Mercury Loop

    CERN Document Server

    Stefan Joray

    The cooling of the mercury loop is described on pages two, three and four. The gaps in the water jackets of the heat exchangers are too large and the cooling water capacity is too low. Convection from the wall into water is bad. The mercury temperature is too high. On page five is a proposal how the mercury temperature can be kept low and constant.

  7. House Prices and Taxes

    DEFF Research Database (Denmark)

    Gjedsted Nielsen, Mads

    This paper is the first to consider a large scale natural experiment to estimate the effect of taxes on house prices. We find that a 1 percentage-point increase in income tax rates lead to a drop in house prices of at most 2.2%. This corresponds to a tax capitalization for the average household...... capitalization from earlier studies. Furthermore, we find no effect of property taxes on house prices. We attribute this to the low levels of Danish municipal property tax rates compared to income tax rates....

  8. Higher dimensional loop quantum cosmology

    International Nuclear Information System (INIS)

    Zhang, Xiangdong

    2016-01-01

    Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n + 1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n + 1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n + 1 dimensional model and the 3 + 1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology. (orig.)

  9. City of Ljubljana: Its housing, population and housing conditions

    Directory of Open Access Journals (Sweden)

    Maša Filipovič

    2007-01-01

    Full Text Available The article gives an overview of key aspect of housing in Municipality of Ljubljana. The characteristics of households, of housing and their relation influence the housing situation in the city. Characteristic of housing refer mainly to quality of the dwellings, affordability and correspondence to the wishes of the inhabitants. The second important dimensions are households and their characteristics. In Europe and Slovenia increase in number of household can be observed, which in turn are becoming smaller. The housing policy has a role in establishing a balance between households and housing, i.e. ensuring that housing corresponds to the needs of individual households and to their number. For achieving this, knowledge and appropriate data are of vital importance. In the article we present the results of the Housing survey 2005. We observe housing conditions in a comparative perspective (Ljubljana in comparison to Maribor, Slovenia and selected European cities and according to three dimensions: housing fund, households and housing conditions.

  10. Actively convected liquid metal divertor

    International Nuclear Information System (INIS)

    Shimada, Michiya; Hirooka, Yoshi

    2014-01-01

    The use of actively convected liquid metals with j × B force is proposed to facilitate heat handling by the divertor, a challenging issue associated with magnetic fusion experiments such as ITER. This issue will be aggravated even more for DEMO and power reactors because the divertor heat load will be significantly higher and yet the use of copper would not be allowed as the heat sink material. Instead, reduced activation ferritic/martensitic steel alloys with heat conductivities substantially lower than that of copper, will be used as the structural materials. The present proposal is to fill the lower part of the vacuum vessel with liquid metals with relatively low melting points and low chemical activities including Ga and Sn. The divertor modules, equipped with electrodes and cooling tubes, are immersed in the liquid metal. The electrode, placed in the middle of the liquid metal, can be biased positively or negatively with respect to the module. The j × B force due to the current between the electrode and the module provides a rotating motion for the liquid metal around the electrodes. The rise in liquid temperature at the separatrix hit point can be maintained at acceptable levels from the operation point of view. As the rotation speed increases, the current in the liquid metal is expected to decrease due to the v × B electromotive force. This rotating motion in the poloidal plane will reduce the divertor heat load significantly. Another important benefit of the convected liquid metal divertor is the fast recovery from unmitigated disruptions. Also, the liquid metal divertor concept eliminates the erosion problem. (letter)

  11. Evaluation of system codes for analyzing naturally circulating gas loop

    International Nuclear Information System (INIS)

    Lee, Jeong Ik; No, Hee Cheon; Hejzlar, Pavel

    2009-01-01

    Steady-state natural circulation data obtained in a 7 m-tall experimental loop with carbon dioxide and nitrogen are presented in this paper. The loop was originally designed to encompass operating range of a prototype gas-cooled fast reactor passive decay heat removal system, but the results and conclusions are applicable to any natural circulation loop operating in regimes having buoyancy and acceleration parameters within the ranges validated in this loop. Natural circulation steady-state data are compared to numerical predictions by two system analysis codes: GAMMA and RELAP5-3D. GAMMA is a computational tool for predicting various transients which can potentially occur in a gas-cooled reactor. The code has a capability of analyzing multi-dimensional multi-component mixtures and includes models for friction, heat transfer, chemical reaction, and multi-component molecular diffusion. Natural circulation data with two gases show that the loop operates in the deteriorated turbulent heat transfer (DTHT) regime which exhibits substantially reduced heat transfer coefficients compared to the forced turbulent flow. The GAMMA code with an original heat transfer package predicted conservative results in terms of peak wall temperature. However, the estimated peak location did not successfully match the data. Even though GAMMA's original heat transfer package included mixed-convection regime, which is a part of the DTHT regime, the results showed that the original heat transfer package could not reproduce the data with sufficient accuracy. After implementing a recently developed correlation and corresponding heat transfer regime map into GAMMA to cover the whole range of the DTHT regime, we obtained better agreement with the data. RELAP5-3D results are discussed in parallel.

  12. In-house (disability

    Directory of Open Access Journals (Sweden)

    Safak Pavey

    2010-07-01

    Full Text Available In May 2007 UNHCR established an internal working group to look at developing in-house policies for people with disabilities both for the benefit of people of concern to us and for staff members.

  13. Finn Juhl's House

    DEFF Research Database (Denmark)

    Munch, Anders V.; Ottensten, Lizette

    Introduction to the architecture, interior design and design items of the Danish designer Finn Juhl's own house, built 1942 in Ordrup, north of Copenhagen. The interior setting is interpreted on the background of Juhl's many writings on design....

  14. Sustainable Housing Design

    DEFF Research Database (Denmark)

    Lauring, Gert Michael

    2016-01-01

    Sustainable Housing Design. Integrating technical and housing quality aspects of sustainable architecture in civil engineering education. Summary An integrated design approach to sustainable architecture is outlined that combines concerns for zero energy building, good indoor climate and adequate...... phases. The outcome shows that integrated design further solutions where sustainable urban forms of settlement can be highly energy efficient while also attractive from a user perspective. Key words: Sustainable architecture, integrated design, zero-energy-housing, dense urban living. 1. Introduction...... When designing sustainable housing, energy optimization and satisfactory indoor climates are central issues that need to be incorporated from early design phases if to reach a coherent design. It might also be argued that the energy consumption of contemporary buildings only plays a rela-tively minor...

  15. The Eco House

    Energy Technology Data Exchange (ETDEWEB)

    Hobbett, A. (Leicester Ecology Trust (United Kingdom))

    The Eco House is a former park keeper's lodge on the periphery of Leicester's largest public park. Taken over by Leicester Ecology Trust in 1990, the Eco House was a successor to the Trust's earlier low energy house. This has been a local authority decant house, retrofitted to show the potential for increased energy efficiency in older buildings. Many of the ideas from the earlier project were adopted by the new with a widening of its remit to include all matters of environmental concern connected with people's homes. So in addition to energy efficiency, other issues addressed include conservation of resources, wildlife, organic gardening, food production, water, environmental consumerism, recycling and health. Given that the use of energy is regarded by many environmentalists to be the single most important environmental issue today, and one which is easiest for households to address, it remains the project's dominant theme. (author)

  16. Allegheny County Housing Tenure

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Home ownership provides a number of financial, social, and health benefits to American families. Especially in areas with housing price appreciation, home ownership...

  17. House of Generations

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte

    2017-01-01

    only the benefits of living close to the family. The Aarhus Municipality project "House of Generations" is a vision for creating a framework for relationships across all generations, for meaningful encounters and for rewarding neighbourliness. Three of Aarhus Municipality's magistrate departments...... participate in the project: Health and Care, Children and Youth, and Social Conditions and Employment. A public housing association that provides student dorms also participates in the project. The physical framework will be a building with a total area of approx. 25,000 m², located at Pier 4, at Aarhus......' harbour areas. The building will be a multi-generational house comprising a mixture of flexible public housing units for students, the elderly and residents who require care (elderly disabled people and people with acquired brain injuries). The building will be connected with common areas located in close...

  18. State Housing Revival

    DEFF Research Database (Denmark)

    Donovan, Elizabeth

    2015-01-01

    Government funded housing for people in need is a challenge many countries face around the world. This research investigates how to sustainably regenerate post-war suburban state housing in New Zealand, in particular, the suburb of Glen Innes in Auckland. Reviving the community and regenerating...... the buildings is essential for improving the overall quality of the neighbourhoods both socially and physically. Achieving this in a holistic sustainable manner illustrates that there are alternatives to demolition and new builds, as the answer to the current housing shortage problems. New Zealand is confronted...... with the dilemma of what to do with existing government-funded housing which are no longer socially or physically suitable for the current demographic. New Zealand has a large cultural diversity with many new immigrants from the Pacific Islands and Asia. There is a need for culturally flexible and inclusive...

  19. Rental Housing Finance Survey

    Data.gov (United States)

    Department of Housing and Urban Development — The purpose of the RHFS is to provide current and continuous measure of the financial health and property characteristics of single-family and multifamily rental...

  20. access to adequate housing

    African Journals Online (AJOL)

    Nicola Smit

    chauffeurs and restaurant/hotel workers approached the Development Action ..... 10 Ibid. 11 Budget speech by LN Sisulu, Minister of Housing, 28 May 2008, available at .... exorbitantly high property prices in the Cape Town CBD and environs, ...

  1. White House Communications Agency

    National Research Council Canada - National Science Library

    Gimble, Thomas

    1995-01-01

    ...; and the Deputy Secretary of Defense requested the audit. The Deputy Secretary of Defense emphasized that this review should be as thorough as possible of all White House Communications Agency (WHCA...

  2. LoopIng: a template-based tool for predicting the structure of protein loops.

    KAUST Repository

    Messih, Mario Abdel; Lepore, Rosalba; Tramontano, Anna

    2015-01-01

    ) and significant enhancements for long loops (11-20 residues). The quality of the predictions is robust to errors that unavoidably affect the stem regions when these are modeled. The method returns a confidence score for the predicted template loops and has

  3. Radiation protection housing

    Energy Technology Data Exchange (ETDEWEB)

    Maier, A

    1975-04-10

    The radiation protection housing consists of a foot rim with castor swivel wheels, a tubular frame tapering off at the top, and a crown. In the upper part of the tubular frame a lead glass window is permanently installed. The sides are covered with radiation attenuating curtains of leaded rubber. The housing has the shape of a truncated pyramid which can be dismantled into its constituent parts. It is used for protection from radiation encountered in X-ray facilities in dental radiology.

  4. Housing Characteristics, 1990

    International Nuclear Information System (INIS)

    1992-01-01

    This report on energy consumption in the residential sector covers the following topics: housing trends 1980--1990, new housing trends, availability and usage of natural gas by households, changes in appliance usage (refrigerators, entertainment appliances, cooking appliances, convenience appliances), age of major household appliances and equipment, household energy conservation activities, demand-side management programs, and a portrait of households using solar or wood as a source of energy

  5. Passive houses in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Halse, Andreas

    2008-12-15

    The paper analyzes the introduction of passive houses in the Norwegian house market. Passive houses are houses with extremely low levels of energy consumption for heating, and have not yet been built in Norway, but have started to enter the market in Germany and some other countries. The construction sector is analyzed as a sectoral innovation system. The different elements of the innovation system are studied. This includes government agencies, producers, consumers, finance and education. The analysis shows that passive and low-energy houses are on the verge of market breakthrough. This can partly be explained by economic calculations, and partly by processes of learning and change in the institutional set-up of the sector. The construction sector is a sector characterized by low innovative intensity and little interaction between different agents. Those working to promote passive houses have to some extent managed to cope with these challenges. This has happened by breaking away from the traditional focus of Norwegian energy efficiency policies on technology and the economically rational agents, by instead focusing on knowledge and institutional change at the level of the producers. (Author)

  6. Housing and child health.

    Science.gov (United States)

    Weitzman, Michael; Baten, Ahmareen; Rosenthal, David G; Hoshino, Risa; Tohn, Ellen; Jacobs, David E

    2013-09-01

    The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health. Copyright © 2013 Mosby, Inc. All rights reserved.

  7. The Nordic Housing Enabler

    DEFF Research Database (Denmark)

    Helle, T.; Nygren, C.; Slaug, B.

    2014-01-01

    This study addresses development of a content-valid cross-Nordic version of the Housing Enabler and investigation of its inter-rater reliability when used in occupational therapy rating situations, involving occupational therapists, clients, and their home environments. The instrument was transla......This study addresses development of a content-valid cross-Nordic version of the Housing Enabler and investigation of its inter-rater reliability when used in occupational therapy rating situations, involving occupational therapists, clients, and their home environments. The instrument...... was translated from the original Swedish version of the Housing Enabler, and adapted according to accessibility norms and guidelines for housing design in Sweden, Denmark, Finland, and Iceland. This iterative process involved occupational therapists, architects, building engineers, and professional translators......, resulting in the Nordic Housing Enabler. For reliability testing, the sampling strategy and data collection procedures used were the same in all countries. Twenty voluntary occupational therapists, pair-wise but independently of each other, collected data from 106 cases by means of the Nordic Housing...

  8. Rogowski Loop design for NSTX

    International Nuclear Information System (INIS)

    McCormack, B.; Kaita, R.; Kugel, H.; Hatcher, R.

    2000-01-01

    The Rogowski Loop is one of the most basic diagnostics for tokamak operations. On the National Spherical Torus Experiment (NSTX), the plasma current Rogowski Loop had the constraints of the very limited space available on the center stack, 5,000 volt isolation, flexibility requirements as it remained a part of the Center Stack assembly after the first phase of operation, and a +120 C temperature requirement. For the second phase of operation, four Halo Current Rogowski Loops under the Center Stack tiles will be installed having +600 C and limited space requirements. Also as part of the second operational phase, up to ten Rogowski Loops will installed to measure eddy currents in the Passive Plate support structures with +350 C, restricted space, and flexibility requirements. This presentation will provide the details of the material selection, fabrication techniques, testing, and installation results of the Rogowski Loops that were fabricated for the high temperature operational and bakeout requirements, high voltage isolation requirements, and the space and flexibility requirements imposed upon the Rogowski Loops. In the future operational phases of NSTX, additional Rogowski Loops could be anticipated that will measure toroidal plasma currents in the vacuum vessel and in the Passive Plate assemblies

  9. A thermodynamically general theory for convective vortices

    Science.gov (United States)

    Renno, Nilton O.

    2008-08-01

    Convective vortices are common features of atmospheres that absorb lower-entropy-energy at higher temperatures than they reject higher-entropy-energy to space. These vortices range from small to large-scale and play an important role in the vertical transport of heat, momentum, and tracer species. Thus, the development of theoretical models for convective vortices is important to our understanding of some of the basic features of planetary atmospheres. The heat engine framework is a useful tool for studying convective vortices. However, current theories assume that convective vortices are reversible heat engines. Since there are questions about how reversible real atmospheric heat engines are, their usefulness for studying real atmospheric vortices is somewhat controversial. In order to reduce this problem, a theory for convective vortices that includes irreversible processes is proposed. The paper's main result is that the proposed theory provides an expression for the pressure drop along streamlines that includes the effects of irreversible processes. It is shown that a simplified version of this expression is a generalization of Bernoulli's equation to convective circulations. It is speculated that the proposed theory not only explains the intensity, but also sheds light on other basic features of convective vortices such as their physical appearance.

  10. Housing management and maintenance practise of Dutch housing associations

    NARCIS (Netherlands)

    Straub, A.

    This paper summarises the state-of-the-art in housing management and maintenance practise of Dutch housing associations based on a survey conducted among almost all housing associations. We address the question what the current developments are in housing management and maintenance practice in the

  11. Two-loop hard-thermal-loop thermodynamics with quarks

    International Nuclear Information System (INIS)

    Andersen, Jens O.; Petitgirard, Emmanuel; Strickland, Michael

    2004-01-01

    We calculate the quark contribution to the free energy of a hot quark-gluon plasma to two-loop order using hard-thermal-loop (HTL) perturbation theory. All ultraviolet divergences can be absorbed into renormalizations of the vacuum energy and the HTL quark and gluon mass parameters. The quark and gluon HTL mass parameters are determined self-consistently by a variational prescription. Combining the quark contribution with the two-loop HTL perturbation theory free energy for pure glue we obtain the total two-loop QCD free energy. Comparisons are made with lattice estimates of the free energy for N f =2 and with exact numerical results obtained in the large-N f limit

  12. Boundary Layer Control of Rotating Convection Systems

    Science.gov (United States)

    King, E. M.; Stellmach, S.; Noir, J.; Hansen, U.; Aurnou, J. M.

    2008-12-01

    Rotating convection is ubiquitous in the natural universe, and is likely responsible for planetary processes such magnetic field generation. Rapidly rotating convection is typically organized by the Coriolis force into tall, thin, coherent convection columns which are aligned with the axis of rotation. This organizational effect of rotation is thought to be responsible for the strength and structure of magnetic fields generated by convecting planetary interiors. As thermal forcing is increased, the relative influence of rotation weakens, and fully three-dimensional convection can exist. It has long been assumed that rotational effects will dominate convection dynamics when the ratio of buoyancy to the Coriolis force, the convective Rossby number, Roc, is less than unity. We investigate the influence of rotation on turbulent Rayleigh-Benard convection via a suite of coupled laboratory and numerical experiments over a broad parameter range: Rayleigh number, 10310; Ekman number, 10-6≤ E ≤ ∞; and Prandtl number, 1≤ Pr ≤ 100. In particular, we measure heat transfer (as characterized by the Nusselt number, Nu) as a function of the Rayleigh number for several different Ekman and Prandtl numbers. Two distinct heat transfer scaling regimes are identified: non-rotating style heat transfer, Nu ~ Ra2/7, and quasigeostrophic style heat transfer, Nu~ Ra6/5. The transition between the non-rotating regime and the rotationally dominant regime is described as a function of the Ekman number, E. We show that the regime transition depends not on the global force balance Roc, but on the relative thicknesses of the thermal and Ekman boundary layers. The transition scaling provides a predictive criterion for the applicability of convection models to natural systems such as Earth's core.

  13. String breaking with Wilson loops?

    CERN Document Server

    Kratochvila, S; Kratochvila, Slavo; Forcrand, Philippe de

    2003-01-01

    A convincing, uncontroversial observation of string breaking, when the static potential is extracted from Wilson loops only, is still missing. This failure can be understood if the overlap of the Wilson loop with the broken string is exponentially small. In that case, the broken string ground state will only be seen if the Wilson loop is long enough. Our preliminary results show string breaking in the context of the 3d SU(2) adjoint static potential, using the L\\"uscher-Weisz exponential variance reduction approach. As a by-product, we measure the fundamental SU(2) static potential with improved accuracy and see clear deviations from Casimir scaling.

  14. BMN correlators by loop equations

    International Nuclear Information System (INIS)

    Eynard, Bertrand; Kristjansen, Charlotte

    2002-01-01

    In the BMN approach to N=4 SYM a large class of correlators of interest are expressible in terms of expectation values of traces of words in a zero-dimensional gaussian complex matrix model. We develop a loop-equation based, analytic strategy for evaluating such expectation values to any order in the genus expansion. We reproduce the expectation values which were needed for the calculation of the one-loop, genus one correction to the anomalous dimension of BMN-operators and which were earlier obtained by combinatorial means. Furthermore, we present the expectation values needed for the calculation of the one-loop, genus two correction. (author)

  15. Understanding Housing Delays and Relocations Within the Housing First Model.

    Science.gov (United States)

    Zerger, Suzanne; Pridham, Katherine Francombe; Jeyaratnam, Jeyagobi; Hwang, Stephen W; O'Campo, Patricia; Kohli, Jaipreet; Stergiopoulos, Vicky

    2016-01-01

    This study explores factors contributing to delays and relocations during the implementation of the Housing First model in Toronto, Ontario. While interruptions in housing tenure are expected en route to recovery and housing stability, consumer and service provider views on finding and keeping housing remain largely unknown. In-person interviews and focus groups were conducted with 48 study participants, including 23 case managers or housing workers and 25 consumers. The following three factors contributed to housing delays and transfers: (1) the effectiveness of communication and collaboration among consumers and service providers, (2) consumer-driven preferences and ambivalence, and (3) provider prioritization of consumer choice over immediate housing access. Two strategies--targeted communications and consumer engagement in housing searches--supported the housing process. Several factors affect the timing and stability of housing. Communication between and among providers and consumers, and a shared understanding of consumer choice, can further support choice and recovery.

  16. Measuring Convective Mass Fluxes Over Tropical Oceans

    Science.gov (United States)

    Raymond, David

    2017-04-01

    Deep convection forms the upward branches of all large-scale circulations in the tropics. Understanding what controls the form and intensity of vertical convective mass fluxes is thus key to understanding tropical weather and climate. These mass fluxes and the corresponding conditions supporting them have been measured by recent field programs (TPARC/TCS08, PREDICT, HS3) in tropical disturbances considered to be possible tropical storm precursors. In reality, this encompasses most strong convection in the tropics. The measurements were made with arrays of dropsondes deployed from high altitude. In some cases Doppler radar provided additional measurements. The results are in some ways surprising. Three factors were found to control the mass flux profiles, the strength of total surface heat fluxes, the column-integrated relative humidity, and the low to mid-tropospheric moist convective instability. The first two act as expected, with larger heat fluxes and higher humidity producing more precipitation and stronger lower tropospheric mass fluxes. However, unexpectedly, smaller (but still positive) convective instability produces more precipitation as well as more bottom-heavy convective mass flux profiles. Furthermore, the column humidity and the convective instability are anti-correlated, at least in the presence of strong convection. On spatial scales of a few hundred kilometers, the virtual temperature structure appears to be in dynamic balance with the pattern of potential vorticity. Since potential vorticity typically evolves on longer time scales than convection, the potential vorticity pattern plus the surface heat fluxes then become the immediate controlling factors for average convective properties. All measurements so far have taken place in regions with relatively flat sea surface temperature (SST) distributions. We are currently seeking funding for a measurement program in the tropical east Pacific, a region that exhibits strong SST gradients and

  17. Transient Mixed Convection Validation for NGNP

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Barton [Utah State Univ., Logan, UT (United States); Schultz, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-19

    The results of this project are best described by the papers and dissertations that resulted from the work. They are included in their entirety in this document. They are: (1) Jeff Harris PhD dissertation (focused mainly on forced convection); (2) Blake Lance PhD dissertation (focused mainly on mixed and transient convection). This dissertation is in multi-paper format and includes the article currently submitted and one to be submitted shortly; and, (3) JFE paper on CFD Validation Benchmark for Forced Convection.

  18. Convective cells and transport in toroidal plasmas

    International Nuclear Information System (INIS)

    Hassam, A.B.; Kulsrud, R.M.

    1978-12-01

    The properties of convective cells and the diffusion resulting from such cells are significantly influenced by an inhomogeneity in the extermal confining magnetic field, such as that in toroidal plasmas. The convective diffusion in the presence of a field inhomogeneity is estimated. For a thermal background, this diffusion is shown to be substantially smaller than classical collisional diffusion. For a model nonthermal background, the diffusion is estimated, for typical parameters, to be at most of the order of collisional diffusion. The model background employed is based on spectra observed in numerical simulations of drift-wave-driven convective cells

  19. Transient Mixed Convection Validation for NGNP

    International Nuclear Information System (INIS)

    Smith, Barton; Schultz, Richard

    2015-01-01

    The results of this project are best described by the papers and dissertations that resulted from the work. They are included in their entirety in this document. They are: (1) Jeff Harris PhD dissertation (focused mainly on forced convection); (2) Blake Lance PhD dissertation (focused mainly on mixed and transient convection). This dissertation is in multi-paper format and includes the article currently submitted and one to be submitted shortly; and, (3) JFE paper on CFD Validation Benchmark for Forced Convection.

  20. Optical loop framing

    International Nuclear Information System (INIS)

    Kalibjian, R.; Chong, Y.P.; Prono, D.S.; Cavagnolo, H.R.

    1984-06-01

    The ATA provides an electron beam pulse of 70-ns duration at a 1-Hz rate. Our present optical diagnostics technique involve the imaging of the visible light generated by the beam incident onto the plant of a thin sheet of material. It has already been demonstrated that the light generated has a sufficiently fast temporal reponse in performing beam diagnostics. Notwithstanding possible beam emittance degradation due to scattering in the thin sheet, the observation of beam spatial profiles with relatively high efficiencies has provided data complementary to that obtained from beam wall current monitors and from various x-ray probes and other electrical probes. The optical image sensor consists of a gated, intensified television system. The gate pulse of the image intensifier can be appropriately delayed to give frames that are time-positioned from the head to the tail of the beam with a minimum gate time of 5-ns. The spatial correlation of the time frames from pulse to pulse is very good for a stable electron beam; however, when instabilities do occur, it is difficult to properly assess the spatial composition of the head and the tail of the beam on a pulse-to-pulse basis. Multiple gating within a pulse duration becomes desirable but cannot be performed because the recycle time (20-ms) of the TV system is much longer than the beam pulse. For this reason we have developed an optical-loop framing technique that will allow the recording of two frames within one pulse duration with our present gated/intensified TV system

  1. Constructing passive houses

    Energy Technology Data Exchange (ETDEWEB)

    Oehler, S. [Oehler Faigle Archkom Solar Architektur, Bretten (Germany)

    2005-07-01

    Everybody can learn to build energy-efficient. It needs theoretical and practical experience. 1997 we built the first freestanding Passive House in Europe, the Passive House Oehler. There had been a lot of questions, starting with the insecurity, whether the calculation program of the Passive House Institute, the PHPP, is working properly in our case. Nobody knew at that time because nobody tried it out before. It took us a lot of time to find out and every detail of the construction hat to be invented to meet the very high demand of thermal quality. All the following houses needed less time and had fewer open questions, adding one piece of experience with every building. 2002 we realised the biggest Passive House, the office building Energon Ulm with 420 working spaces. In the meantime we have learned a lot like how to produce prefabricated timber elements for the facades, providing good insulation, air tightness and avoiding serious thermal bridges. We have proofed, that any kind of building type can be a Passive House. And with increasing experience the freedom of design and construction is growing. Even the economical efficiency increased. The Energon Ulm is providing a much better indoor climate than any other office building and was build 10 % cheaper than an average German office building. At present the Passive House Standard is the most efficient solution for the user to live in the desired comfort zone between 20 C and 25 C. This zone of individual feeling-well can be described with the term ''operative temperature''. This term is defined by factors like air temperature, radiation temperature of warm and cold surfaces, air speed and humidity. The result of all these factors has to be within 18 C to 25 C without accepting one of the factors getting extreme.

  2. Passive House Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Strom, I.; Joosten, L.; Boonstra, C. [DHV Sustainability Consultants, Eindhoiven (Netherlands)

    2006-05-15

    PEP stands for 'Promotion of European Passive Houses' and is a consortium of European partners, supported by the European Commission, Directorate General for Energy and Transport. In this working paper an overview is given of Passive House solutions. An inventory has been made of Passive House solutions for new build residences applied in each country. Based on this, the most common basic solutions have been identified and described in further detail, including the extent to which solutions are applied in common and best practice and expected barriers for the implementation in each country. An inventory per country is included in the appendix. The analysis of Passive House solutions in partner countries shows high priority with regard to the performance of the thermal envelope, such as high insulation of walls, roofs, floors and windows/ doors, thermal bridge-free construction and air tightness. Due to the required air tightness, special attention must be paid to indoor air quality through proper ventilation. Finally, efficient ((semi-)solar) heating systems for combined space and DHW heating still require a significant amount of attention in most partner countries. Other basic Passive House solutions show a smaller discrepancy with common practice and fewer barriers have been encountered in partner countries. In the next section, the general barriers in partner countries have been inventoried. For each type of barrier a suggested approach has been given. Most frequently encountered barriers in partner countries are: limited know-how; limited contractor skills; and acceptation of Passive Houses in the market. Based on the suggested approaches to overcoming barriers, this means that a great deal of attention must be paid to providing practical information and solutions to building professionals, providing practical training to installers and contractors and communication about the Passive House concept to the market.

  3. Housing and family: an introduction

    NARCIS (Netherlands)

    Mulder, C.H.; Lauster, N.T.

    2010-01-01

    This paper introduces the Housing Studies special issue 'Housing and Family'. The issue consists of a collection of papers in which a number of connections between housing and family issues are highlighted. Three themes are addressed: the influence of the family of origin on housing characteristics

  4. Convection in complex shaped vessel; Convection dans des enceintes de forme complexe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The 8 november 2000, the SFT (Societe Francaise de Thermique) organized a technical day on the convection in complex shaped vessels. Nine papers have been presented in the domains of the heat transfers, the natural convection, the fluid distribution, the thermosyphon effect, the steam flow in a sterilization cycle and the transformers cooling. Eight papers are analyzed in ETDE and one paper dealing with the natural convection in spent fuels depository is analyzed in INIS. (A.L.B.)

  5. Domotics Project Housing Block

    Science.gov (United States)

    Morón, Carlos; Payán, Alejandro; García, Alfonso; Bosquet, Francisco

    2016-01-01

    This document develops the study of an implementation project of a home automation system in a housing placed in the town of Galapagar, Madrid. This house, which is going to be occupied by a four-member family, consists of 67 constructed square meters distributed in lounge, kitchen, three bedrooms, bath, bathroom and terrace, this being a common arrangement in Spain. Thus, this study will allow extracting conclusions about the adequacy of the home automation in a wide percentage of housing in Spain. In this document, three house automation proposals are developed based on the requirements of the client and the different home automation levels that the Spanish House and Building Automation Association has established, besides two parallel proposals relating to the safety and the technical alarms. The mentioned proposed systems are described by means of product datasheets and descriptions, distribution plans, measurements, budgets and flow charts that describe the functioning of the system in every case. An evaluation of each system is included, based on other studies conclusions on this matter, where expected energy savings from each design, depending on the current cost of lighting, water and gas, as well as the expected economic amortization period is evaluated. PMID:27223285

  6. Domotics Project Housing Block.

    Science.gov (United States)

    Morón, Carlos; Payán, Alejandro; García, Alfonso; Bosquet, Francisco

    2016-05-23

    This document develops the study of an implementation project of a home automation system in a housing placed in the town of Galapagar, Madrid. This house, which is going to be occupied by a four-member family, consists of 67 constructed square meters distributed in lounge, kitchen, three bedrooms, bath, bathroom and terrace, this being a common arrangement in Spain. Thus, this study will allow extracting conclusions about the adequacy of the home automation in a wide percentage of housing in Spain. In this document, three house automation proposals are developed based on the requirements of the client and the different home automation levels that the Spanish House and Building Automation Association has established, besides two parallel proposals relating to the safety and the technical alarms. The mentioned proposed systems are described by means of product datasheets and descriptions, distribution plans, measurements, budgets and flow charts that describe the functioning of the system in every case. An evaluation of each system is included, based on other studies conclusions on this matter, where expected energy savings from each design, depending on the current cost of lighting, water and gas, as well as the expected economic amortization period is evaluated.

  7. Domotics Project Housing Block

    Directory of Open Access Journals (Sweden)

    Carlos Morón

    2016-05-01

    Full Text Available This document develops the study of an implementation project of a home automation system in a housing placed in the town of Galapagar, Madrid. This house, which is going to be occupied by a four-member family, consists of 67 constructed square meters distributed in lounge, kitchen, three bedrooms, bath, bathroom and terrace, this being a common arrangement in Spain. Thus, this study will allow extracting conclusions about the adequacy of the home automation in a wide percentage of housing in Spain. In this document, three house automation proposals are developed based on the requirements of the client and the different home automation levels that the Spanish House and Building Automation Association has established, besides two parallel proposals relating to the safety and the technical alarms. The mentioned proposed systems are described by means of product datasheets and descriptions, distribution plans, measurements, budgets and flow charts that describe the functioning of the system in every case. An evaluation of each system is included, based on other studies conclusions on this matter, where expected energy savings from each design, depending on the current cost of lighting, water and gas, as well as the expected economic amortization period is evaluated.

  8. Control rod housing alignment

    International Nuclear Information System (INIS)

    Dixon, R.C.; Deaver, G.A.; Punches, J.R.; Singleton, G.E.; Erbes, J.G.; Offer, H.P.

    1990-01-01

    This patent describes a process for measuring the vertical alignment between a hole in a core plate and the top of a corresponding control rod drive housing within a boiling water reactor. It comprises: providing an alignment apparatus. The alignment apparatus including a lower end for fitting to the top of the control rod drive housing; an upper end for fitting to the aperture in the core plate, and a leveling means attached to the alignment apparatus to read out the difference in angularity with respect to gravity, and alignment pin registering means for registering to the alignment pin on the core plate; lowering the alignment device on a depending support through a lattice position in the top guide through the hole in the core plate down into registered contact with the top of the control rod drive housing; registering the upper end to the sides of the hole in the core plate; registering the alignment pin registering means to an alignment pin on the core plate to impart to the alignment device the required angularity; and reading out the angle of the control rod drive housing with respect to the hole in the core plate through the leveling devices whereby the angularity of the top of the control rod drive housing with respect to the hole in the core plate can be determined

  9. Social Housing Provision in Copenhagen

    DEFF Research Database (Denmark)

    Tsenkova, Sasha; Vestergaard, Hedvig

    -profit housing providers, and a wide range of fiscal and regulatory instruments enhancing the competitive performance of the social housing sector. The research analyses recent housing policy measures and their impact on new social housing provision in Copenhagen. The emphasis is on the mix of housing policy......The paper provides an overview of trends and processes of change affecting new social housing provision in Denmark with a focus on Copenhagen. The local responses are reviewed within the context of changes to the unitary national housing system that functions with a robust range of private and non...... instruments implemented in three major policy domains-fiscal, financial and regulatory-to promote the production of new social housing. The system of new social housing provision is examined as a dynamic process of interaction between public and private institutions defining housing policy outcomes...

  10. Effect of non-condensable gas on startup of a loop thermosyphon

    International Nuclear Information System (INIS)

    He, Jiang; Lin, Guiping; Bai, Lizhan; Miao, Jianyin; Zhang, Hongxing; Wang, Lu

    2013-01-01

    Non-condensable gas (NCG) generated inside two-phase heat transfer devices can adversely affect the thermal performance and limit the lifetime of such devices. In this work, experimental investigation of the effect of NCG on the startup of an ammonia-stainless steel loop thermosyphon was conducted. In the experiment, nitrogen was injected into the loop thermosyphon as NCG. The effect of NCG inventory on the startup behavior was investigated by adjusting the injected amount of nitrogen. The experimental results reveal that NCG prolongs the startup time and increases the startup liquid superheat and temperature overshoot; the more NCG exists in the loop thermosyphon, the higher the liquid superheat and temperature overshoot. When NCG is present in the system, boiling usually occurs in the evaporator before startup, but it does not mean the system will start up instantly, which differs from the conditions without NCG. Under all the conditions, increasing the heat load can effectively shorten the startup time but leads to a large temperature overshoot; forced convection cooling of the condenser has almost no effect on shortening the startup time especially for large NCG inventory situations, but it can effectively limit the temperature overshoot. For large NCG inventory situations, the loop thermosyphon can start up at a small heat load (5 W) or even without a heat load when the condenser is cooled by forced convection of ethanol. No failed start-ups occurred during any of the tests. (authors)

  11. Steady, three-dimensional, internally heated convection

    International Nuclear Information System (INIS)

    Schubert, G.; Glatzmaier, G.A.; Travis, B.

    1993-01-01

    Numerical calculations have been carried out of steady, symmetric, three-dimensional modes of convection in internally heated, infinite Prandtl number, Boussinesq fluids at a Rayleigh number of 1.4x10 4 in a spherical shell with inner/outer radius of 0.55 and in a 3x3x1 rectangular box. Multiple patterns of convection occur in both geometries. In the Cartesian geometry the patterns are dominated by cylindrical cold downflows and a broad hot upwelling. In the spherical geometry the patterns consist of cylindrical cold downwellings centered either at the vertices of a tetrahedron or the centers of the faces of a cube. The cold downflow cylinders are immersed in a background of upwelling within which there are cylindrical hot concentrations (plumes) and hot halos around the downflows. The forced hot upflow return plumes of internally heated spherical convection are fundamentally different from the buoyancy-driven plumes of heated from below convection

  12. Convective Radio Occultations Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Biondi, R. [Atmospheric Radiation Measurement, Washington, DC (United States)

    2016-03-01

    Deep convective systems are destructive weather phenomena that annually cause many deaths and injuries as well as much damage, thereby accounting for major economic losses in several countries. The number and intensity of such phenomena have increased over the last decades in some areas of the globe. Damage is mostly caused by strong winds and heavy rain parameters that are strongly connected to the structure of the particular storm. Convection over land is usually stronger and deeper than over the ocean and some convective systems, known as supercells, also develop tornadoes through processes that remain mostly unclear. The intensity forecast and monitoring of convective systems is one of the major challenges for meteorology because in situ measurements during extreme events are too sparse or unreliable and most ongoing satellite missions do not provide suitable time/space coverage.

  13. Ignition in Convective-Diffusive Systems

    National Research Council Canada - National Science Library

    Law, Chung

    1999-01-01

    ... efficiency as well as the knock and emission characteristics. The ignition event is clearly controlled by the chemical reactions of fuel oxidation and the fluid mechanics of convective and diffusive transport...

  14. Understanding and controlling plasmon-induced convection

    Science.gov (United States)

    Roxworthy, Brian J.; Bhuiya, Abdul M.; Vanka, Surya P.; Toussaint, Kimani C.

    2014-01-01

    The heat generation and fluid convection induced by plasmonic nanostructures is attractive for optofluidic applications. However, previously published theoretical studies predict only nanometre per second fluid velocities that are inadequate for microscale mass transport. Here we show both theoretically and experimentally that an array of plasmonic nanoantennas coupled to an optically absorptive indium-tin-oxide (ITO) substrate can generate >micrometre per second fluid convection. Crucially, the ITO distributes thermal energy created by the nanoantennas generating an order of magnitude increase in convection velocities compared with nanoantennas on a SiO2 base layer. In addition, the plasmonic array alters absorption in the ITO, causing a deviation from Beer-Lambert absorption that results in an optimum ITO thickness for a given system. This work elucidates the role of convection in plasmonic optical trapping and particle assembly, and opens up new avenues for controlling fluid and mass transport on the micro- and nanoscale.

  15. What favors convective aggregation and why?

    Science.gov (United States)

    Muller, Caroline; Bony, Sandrine

    2015-07-01

    The organization of convection is ubiquitous, but its physical understanding remains limited. One particular type of organization is the spatial self-aggregation of convection, taking the form of cloud clusters, or tropical cyclones in the presence of rotation. We show that several physical processes can give rise to self-aggregation and highlight the key features responsible for it, using idealized simulations. Longwave radiative feedbacks yield a "radiative aggregation." In that case, sufficient spatial variability of radiative cooling rates yields a low-level circulation, which induces the upgradient energy transport and radiative-convective instability. Not only do vertically integrated radiative budgets matter but the vertical profile of cooling is also crucial. Convective aggregation is facilitated when downdrafts below clouds are weak ("moisture-memory aggregation"), and this is sufficient to trigger aggregation in the absence of longwave radiative feedbacks. These results shed some light on the sensitivity of self-aggregation to various parameters, including resolution or domain size.

  16. Antartic observations of plasma convection

    International Nuclear Information System (INIS)

    Hansen, H.J.

    1983-01-01

    This thesis is concerned with the use of whistler duct tracking as a diagnostic for the behaviour of plasma in the plasmasphere. As a setting for the results given in the thesis, a broad review is presented which embraces pertinent aspects of previous experimental and theoretical studies of the plasmasphere. From a study of 24 hours of continuous whistler data recorded at Sanae, (L = 3,98), it is shown that associated with quiet magnetic conditions (Av Ksub(p)=1), there exists two plasmasphere bulges centred on about 1700 and 0100 UT. There is evidence that these plasmasphere bulge structures are part of a ground-state or reference base drift pattern. Electric field measurements provide some evidence that quiet time plasmasphere drift behaviour is controlled by the internal ionospheric current systems of dynamo origin, rather than being controlled by magnetospheric convection. Finally, this thesis describes an application of the whistler duct tracking technique to whistler data recorded simultaneously at two ground-based stations (Sanae (L = 3,98) and Halley (L = 4,23)). The identification of common whistler components on each station's data set provides a means of estimating the lifetimes of the associated whistler ducts. Duct lifetimes of as little as 30 minutes are found. Such short lived ducts have important implications for current theories of duct formation

  17. Dynamics of acoustic-convective drying of sunflower cake

    Science.gov (United States)

    Zhilin, A. A.

    2017-10-01

    The dynamics of drying sunflower cake by a new acoustic-convective method has been studied. Unlike the conventional (thermal-convective) method, the proposed method allows moisture to be extracted from porous materials without applying heat to the sample to be dried. Kinetic curves of drying by the thermal-convective and acoustic-convective methods were obtained and analyzed. The advantages of the acoustic-convective extraction of moisture over the thermal-convective method are discussed. The relaxation times of drying were determined for both drying methods. An intermittent drying mode which improves the efficiency of acoustic-convective extraction of moisture is considered.

  18. Progress in construction of liquid metal LiPb experimental loops in China

    International Nuclear Information System (INIS)

    Zhang, M.; Zhu, Z.; Gao, S.; Song, Y.; Li, C.; Huang, Q.; Wu, Y.

    2007-01-01

    The activities of FDS series fusion reactors design with liquid tritium breeder blankets have been performed at ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences) for years. In the designs, CLAM (China Low Activation Martensitic steel), is considered as the primary candidate structural material and LiPb eutectic as both tritium breeder and coolant of the blankets. Therefore, researches on LiPb experimental loop and construction of LiPb loop are severely needed in order to carry out experimental study on the compatibility of candidate structural materials for fusion reactors such as CLAM etc., flowing characteristics of LiPb and Magnetohydrodynamic (MHD) effect and so on, which is essential to researches of China liquid LiPb blankets. A lot of work has been done at ASIPP on design, manufacture and experiments for the series LiPb experimental loops i.e. Dragon-I, Dragon-II, Dragon-III and Dragon-IV. Dragon-I is a thermal convection LiPb loop made of SS316L steel and operating at 500 degree C. The first 3000 hour loop operation at 480 degree C for compatibility test on CLAM was done. Dragon-II and Dragon-III are also thermal convection LiPb loops, made of Inconel 600 and SiCr/SiC, and operating at 700 degree C and 1000 degree C, respectively, to obtain corrosion results of materials such as SiCr/SiC composite. Dragon-II has already been built up and under testing. Dragon-III is under construction. Base on requirement for experiments on characteristics of LiPb on its flow, MHD effect and corrosion to materials, Dragon-IV forced convection loop is being designed. The operation temperature ranges from 480 degree C at the cold leg to 700 degree C at the hot leg, the magnetic field is about 2-5T. Experiments and related studies in those loops are underway. (authors)

  19. CONVECTION IN CONDENSIBLE-RICH ATMOSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Ding, F. [Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637 (United States); Pierrehumbert, R. T., E-mail: fding@uchicago.edu [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom)

    2016-05-01

    Condensible substances are nearly ubiquitous in planetary atmospheres. For the most familiar case—water vapor in Earth’s present climate—the condensible gas is dilute, in the sense that its concentration is everywhere small relative to the noncondensible background gases. A wide variety of important planetary climate problems involve nondilute condensible substances. These include planets near or undergoing a water vapor runaway and planets near the outer edge of the conventional habitable zone, for which CO{sub 2} is the condensible. Standard representations of convection in climate models rely on several approximations appropriate only to the dilute limit, while nondilute convection differs in fundamental ways from dilute convection. In this paper, a simple parameterization of convection valid in the nondilute as well as dilute limits is derived and used to discuss the basic character of nondilute convection. The energy conservation properties of the scheme are discussed in detail and are verified in radiative-convective simulations. As a further illustration of the behavior of the scheme, results for a runaway greenhouse atmosphere for both steady instellation and seasonally varying instellation corresponding to a highly eccentric orbit are presented. The latter case illustrates that the high thermal inertia associated with latent heat in nondilute atmospheres can damp out the effects of even extreme seasonal forcing.

  20. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Tae [Kongju National Univ., Kongju (Korea, Republic of); Song, Kyu Sub [Electronics and Telecommunications Research Institute, Taejon (Korea, Republic of); Lee, Young [Univ. of Ottawa, Ontario (Canada)

    1998-10-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm{sup 2}. The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm{sup 2} with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion.

  1. Design of a two-phase loop thermosyphon for telecommunications system(I): experiments and visualization

    International Nuclear Information System (INIS)

    Kim, Won Tae; Song, Kyu Sub; Lee, Young

    1998-01-01

    A two-phase loop thermosyphon system is developed for the B-ISDN telecommunications system and its performance is evaluated both experimentally and by visualization techniques. The design of the thermosyphon system proposed is aimed to cool MultiChip Modules (MCM) upto heat flux of 8 W/cm 2 . The results indicate that in the loop thermosyphon system cooling heat flux is capable of 12 W/cm 2 with two condensers under the forced convection cooling of the condenser section with acetone or FC-87 as the working fluid. The instability of the working fluid flow within the loop is observed using the visualization techniques and temperature fluctuation is stabilized with orifice insertion

  2. Ideas about housing

    DEFF Research Database (Denmark)

    Earon, Ofri

    2009-01-01

    This booklet is a project documentation of a short-term project titled ‘IDEAS ABOUT HOUSING Arkitektkonkurrencernes boligløsninger’. Architectural competitions have been used to develop new living concepts reacting on current political, economical and social flows. Participation in an architectural...... an important part of the world of architecture and planning in Denmark. Competitions, sponsored by government organizations, housing associations, or private business, are usually requests to make proposals for a specific project, but they are also sometimes used to elicit ideas about a general project type...

  3. GREEN CORE HOUSE

    Directory of Open Access Journals (Sweden)

    NECULAI Oana

    2017-05-01

    Full Text Available The Green Core House is a construction concept with low environmental impact, having as main central element a greenhouse. The greenhouse has the innovative role to use the biomass energy provided by plants to save energy. Although it is the central piece, the greenhouse is not the most innovative part of the Green Core House, but the whole building ensemble because it integrates many other sustainable systems as "waste purification systems", "transparent photovoltaic panels" or "double skin façades".

  4. Preliminary design of a small air loop for system analysis and validation of Cathare code

    International Nuclear Information System (INIS)

    Marchand, M.; Saez, M.; Tauveron, N.; Tenchine, D.; Germain, T.; Geffraye, G.; Ruby, G.P.

    2007-01-01

    The French Atomic Energy Commission (Cea) is carrying on the design of a Small Air Loop for System Analysis (SALSA), devoted to the study of gas cooled nuclear reactors behaviour in normal and incidental/accidental operating conditions. The reduced size of the SALSA components compared to a full-scale reactor and air as gaseous coolant instead of Helium will allow an easy management of the loop. The main purpose of SALSA will be the validation of the associated thermal hydraulic safety simulation codes, like CATHARE. The main goal of this paper is to present the methodology used to define the characteristics of the loop. In a first step, the study has been focused on a direct-cycle system for the SALSA loop with few global constraints using a similarity analysis to support the definition and design of the loop. Similarity requirements have been evaluated to determine the scale factors which have to be applied to the SALSA loop components. The preliminary conceptual design of the SALSA plant with a definition of each component has then be carried out. The whole plant has been modelled using the CATHARE code. Calculations of the SALSA steady-state in nominal conditions and of different plant transients in direct-cycle have been made. The first system results obtained on the global behaviour of the loop confirm that SALSA can be representative of a Gas-Cooled nuclear reactor with some minor design modifications. In a second step, the current prospects focus on the SALSA loop capability to reproduce correctly the heat transfer occurring in specific incidental situations. Heat decay removal by natural convection is a crucial point of interest. The first results show that the behaviour and the efficiency of the loop are strongly influenced by the definition of the main parameters for each component. A complete definition of SALSA is under progress. (authors)

  5. Loop equations in the theory of gravitation

    International Nuclear Information System (INIS)

    Makeenko, Yu.M.; Voronov, N.A.

    1981-01-01

    Loop-space variables (matrices of parallel transport) for the theory of gravitation are described. Loop equations, which are equivalent to the Einstein equations, are derived in the classical case. Loop equations are derived for gravity with cosmological constant as well. An analogy with the loop-space approach in Yang-Mills theory is discussed [ru

  6. Kalman Orbit Optimized Loop Tracking

    Science.gov (United States)

    Young, Lawrence E.; Meehan, Thomas K.

    2011-01-01

    Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

  7. A type of loop algebra and the associated loop algebras

    International Nuclear Information System (INIS)

    Tam Honwah; Zhang Yufeng

    2008-01-01

    A higher-dimensional twisted loop algebra is constructed. As its application, a new Lax pair is presented, whose compatibility gives rise to a Liouville integrable hierarchy of evolution equations by making use of Tu scheme. One of the reduction cases of the hierarchy is an analogous of the well-known AKNS system. Next, the twisted loop algebra, furthermore, is extended to another higher dimensional loop algebra, from which a hierarchy of evolution equations with 11-potential component functions is obtained, whose reduction is just standard AKNS system. Especially, we prove that an arbitrary linear combination of the four Hamiltonian operators directly obtained from the recurrence relations is still a Hamiltonian operator. Therefore, the hierarchy with 11-potential functions possesses 4-Hamiltonian structures. Finally, an integrable coupling of the hierarchy is worked out

  8. Corrosion of an Fe-12 Cr-1 Mo VW steel in thermally-convective lithium

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1983-01-01

    A thermal-convection loop of Fe-12 Cr-1 Mo VW steel circulated pure lithium between 500 and 350 0 C for 10,088 h. Periodic weighings of coupons at different temperatures around the loop revealed small weight losses and corrosion rates. Surface analysis showed a relatively thin corrosion layer with an underlying carbide-free zone and some depletion of chromium from the hottest specimen. While some mass transfer of chromium and nickel was detected, this mechanism did not strongly influence the weight loss process as it does with austenitic steels. Therefore, it appeared that reactions with carbon and nitrogen must be the dominant corrosion processes such that weight loss was maximized at the lowest temperature (350 0 C). Overall, the lithium-steel reactions in the temperature range of this experiment were relatively sluggish and the corrosion was not severe

  9. Housing Problems of Minorities

    Science.gov (United States)

    Weaver, Robert

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, reviews the status of minority group housing and the effects of federal programs upon it, advocating an approach which recognizes the intrinsic locational and real estate value of many black ghettos. (Author/JM)

  10. The Helpful House

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Many everyday tasks are difficult—even impossible for people confined to wheelchairs.Now a unique house near Baltimore,Md., demonstrates how technology can make a building truly accessible. Developed by Volunteers for Medical Engineering in conjunction with several nonprofit organizations, Future Home takes advantage of off-the-shelf electronic controls that operate nearly all electrical and mechanical systems.

  11. Hood River Passive House

    Energy Technology Data Exchange (ETDEWEB)

    Hales, David [BA-PIRC, Spokane, WA (United States)

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  12. The book house

    DEFF Research Database (Denmark)

    Jensen, Niels Henrik; Agger, Steen

    1989-01-01

    user-librarian negotiations. These studies led to the identification of a set of strategies for searching and retrieving literature as well as a mutri-kimensional framework for classifying fiction. Both of these have been necessary prerequisites for the design of the BOOK HOUSE, a flexible on-line data...

  13. Woodworking & housing: impacts & actions

    Science.gov (United States)

    Matt Bumgardner; Urs Buehlmann; Karen. Koenig

    2015-01-01

    The woodworking industry relies heavily on the construction-based markets, particularly those companies involved in cabinetry, furniture, millwork and components. Market conditions, trends and investments all have an impact. It's against this backdrop, that the sixth annual housing market study was conducted in early 2015. A joint effort by Virginia Tech, the U.S...

  14. Housing, neighbourhoods and interventions

    NARCIS (Netherlands)

    Karin Wittebrood; Matthieu Permentier; with contributions from Fenne Pinkster

    2011-01-01

    Original title: Wonen, wijken en interventies Current Dutch neighbourhood policy is aimed at improving the position of 'priority neighbourhoods'. How successful is the policy proving? Does restructuring and the sale of social housing help? Does increasing the amount of green space and building

  15. The Children's House

    Science.gov (United States)

    Peller, Lili E.

    2013-01-01

    Lili Peller's "The Children's House" essay begins where Maria Montessori left off in her description of space articulations. Peller does not name Montessori specifically as she always had a desire to become independent in her own right as a neo-Freudian child analyst. But the Haus Der Kinder founded in summer of 1922 suggests a total…

  16. Interactive Mold House Tour

    Science.gov (United States)

    Get a quick glimpse of some of the most important ways to protect your home from mold by this interactive tour of the Mold House. Room-by-room, you'll learn about common mold issues and how to address them.

  17. Housing First i Danmark

    DEFF Research Database (Denmark)

    Benjaminsen, Lars; Dyrby, Therese Marie; Enemark, Morten Holm

    Rapporten er en evaluering af arbejdet med at udbrede og forankre Housing First-indsatsen og tre evidensbaserede bostøttemetoder. Hovedprincippet i Housing First er, at udsatte borgere, der er endt i hjemløshed, får et permanent sted at bo allerede i starten af et indsatsforløb, samtidig med...... at borgeren får en intensiv social støtte i hverdagen. De evidensbaserede bostøttemetoder, der er anvendes sammen med Housing First-tilgangen er Critical Time Intervention (CTI), Intensive Case Management (ICM) og Assertive Community Treatment (ACT). Rapporten beskriver erfaringer omkring de ledelsesmæssige...... og organisatoriske rammer, målgruppen for indsatserne og om de konkrete indsatser i kommunerne. Evalueringen viser, at både borgere og kommuner har gode erfaringer med Housing First, men at især manglen på billige og passende boliger er en alvorlig barriere for udbredelsen af indsatsen. Evalueringen...

  18. The Chinese House Game.

    Science.gov (United States)

    Lee, James R.

    1989-01-01

    Discussion of the use of simulations to teach international relations (IR) highlights the Chinese House Game, a computer-based decision-making game based on Inter Nation Simulation (INS). Topics discussed include the increasing role of artificial intelligence in IR simulations, multi-disciplinary approaches, and the direction of IR as a…

  19. Housing and construction

    Science.gov (United States)

    Delton Alderman

    2014-01-01

    OECD economies, in aggregate, have been sluggish; unemployment remains high in several countries, and minimal gross domestic product gains are forecast for the Euro area through 2016. Recession, sovereign debt problems and lethargic economies continue to constrain Europe’s housing construction market; no improvement is expected before 2015 or...

  20. Tritium Management Loop Design Status

    Energy Technology Data Exchange (ETDEWEB)

    Rader, Jordan D. [ORNL; Felde, David K. [ORNL; McFarlane, Joanna [ORNL; Greenwood, Michael Scott [ORNL; Qualls, A L. [ORNL; Calderoni, Pattrick [Idaho National Laboratory (INL)

    2017-12-01

    This report summarizes physical, chemical, and engineering analyses that have been done to support the development of a test loop to study tritium migration in 2LiF-BeF2 salts. The loop will operate under turbulent flow and a schematic of the apparatus has been used to develop a model in Mathcad to suggest flow parameters that should be targeted in loop operation. The introduction of tritium into the loop has been discussed as well as various means to capture or divert the tritium from egress through a test assembly. Permeation was calculated starting with a Modelica model for a transport through a nickel window into a vacuum, and modifying it for a FLiBe system with an argon sweep gas on the downstream side of the permeation interface. Results suggest that tritium removal with a simple tubular permeation device will occur readily. Although this system is idealized, it suggests that rapid measurement capability in the loop may be necessary to study and understand tritium removal from the system.

  1. Criteria for saturated magnetization loop

    International Nuclear Information System (INIS)

    Harres, A.; Mikhov, M.; Skumryev, V.; Andrade, A.M.H. de; Schmidt, J.E.; Geshev, J.

    2016-01-01

    Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe_3O_4 and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one. - Highlights: • Proper estimation of hysteresis-loop parameters is vital in magnetic studies. • We propose criteria for discrimination minor from major hysteresis loops. • The criteria analyze magnetization, remanence and ZFC/FC curves and/or their derivatives. • Examples of their application on real nanoparticles systems are given. • Using the criteria could avoid twofold or bigger saturation-field underestimation errors.

  2. Criteria for saturated magnetization loop

    Energy Technology Data Exchange (ETDEWEB)

    Harres, A. [Departamento de Física, UFSM, Santa Maria, 97105-900 Rio Grande do Sul (Brazil); Mikhov, M. [Faculty of Physics, University of Sofia, 1164 Sofia (Bulgaria); Skumryev, V. [Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona (Spain); Departament de Física, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Andrade, A.M.H. de; Schmidt, J.E. [Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil); Geshev, J., E-mail: julian@if.ufrgs.br [Departament de Física, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Instituto de Física, UFRGS, Porto Alegre, 91501-970 Rio Grande do Sul (Brazil)

    2016-03-15

    Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe{sub 3}O{sub 4} and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one. - Highlights: • Proper estimation of hysteresis-loop parameters is vital in magnetic studies. • We propose criteria for discrimination minor from major hysteresis loops. • The criteria analyze magnetization, remanence and ZFC/FC curves and/or their derivatives. • Examples of their application on real nanoparticles systems are given. • Using the criteria could avoid twofold or bigger saturation-field underestimation errors.

  3. 24 CFR 982.608 - Congregate housing: Voucher housing assistance payment.

    Science.gov (United States)

    2010-04-01

    ... Housing Types Congregate Housing § 982.608 Congregate housing: Voucher housing assistance payment. (a... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Congregate housing: Voucher housing assistance payment. 982.608 Section 982.608 Housing and Urban Development Regulations Relating to Housing and...

  4. Vertical natural convection: application of the unifying theory of thermal convection

    NARCIS (Netherlands)

    Ng, C.S.; Ooi, A.; Lohse, Detlef; Chung, D.

    2015-01-01

    Results from direct numerical simulations of vertical natural convection at Rayleigh numbers 1.0×10 5 –1.0×10 9 and Prandtl number 0.709 support a generalised applicability of the Grossmann–Lohse (GL) theory, which was originally developed for horizontal natural (Rayleigh–Bénard) convection. In

  5. Assisted Housing - Public Housing Buildings - National Geospatial Data Asset (NGDA)

    Data.gov (United States)

    Department of Housing and Urban Development — The approximate physical location of each individual Public Housing Building. If the building has more than one entrance or street address, the address of the...

  6. Thermodynamics in Loop Quantum Cosmology

    International Nuclear Information System (INIS)

    Li, L.F.; Zhu, J.Y.

    2009-01-01

    Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. Moreover, the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon of the Friedmann-Robertson-Walker universe as a thermodynamical system and investigate the thermodynamics of LQC in the semiclassical region. The effective density and effective pressure in the modified Friedmann equation from LQC not only determine the evolution of the universe in LQC scenario but also are actually found to be the thermodynamic quantities. This result comes from the energy definition in cosmology (the Misner-Sharp gravitational energy) and is consistent with thermodynamic laws. We prove that within the framework of loop quantum cosmology, the elementary equation of equilibrium thermodynamics is still valid.

  7. Assessment of housing design decisions in informal housing ...

    African Journals Online (AJOL)

    The rapid urbanisation of cities in developing countries has witnessed a growth in the volume of housing construction in the urban areas. The demand for housing and the inability of government to meet this demand has encouraged the growth of informal housing. The concept of healthy buildings is of great importance, ...

  8. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    In this paper an investigation of floor heating systems is performed with respect to heating demand and room temperature. Presently (2001) no commercially available building simulation programs that can be used to evaluate heating demand and thermal comfort in buildings with building integrated....... The model calculates heating demand, room temperatures, and thermal comfort parameters for a person in the room. The model is based on a numerical Finite Control Volume (FCV) method for the heat transfer in walls, ceiling, windows and floor. The model uses both convective and radiative heat transfer...... to the room air and between the room surfaces. The simulation model has been used to calculate heating demand and room temperature in a typical well insulated Danish single-family house with a heating demand of approximately 6000 kWh per year, for a 130 m² house. Two different types of floor heating systems...

  9. High pressure experimental water loop

    International Nuclear Information System (INIS)

    Grenon, M.

    1958-01-01

    A high pressure experimental water loop has been made for studying the detection and evolution of cladding failure in a pressurized reactor. The loop has been designed for a maximum temperature of 360 deg. C, a maximum of 160 kg/cm 2 and flow rates up to 5 m 3 /h. The entire loop consists of several parts: a main circuit with a canned rotor circulation pump, steam pressurizer, heating tubes, two hydro-cyclones (one de-gasser and one decanter) and one tubular heat exchanger; a continuous purification loop, connected in parallel, comprising pressure reducing valves and resin pots which also allow studies of the stability of resins under pressure, temperature and radiation; following the gas separator is a gas loop for studying the recombination of the radiolytic gases in the steam phase. The preceding circuits, as well as others, return to a low pressure storage circuit. The cold water of the low pressure storage flask is continuously reintroduced into the high pressure main circuit by means of a return pump at a maximum head of 160 kg /cm 2 , and adjusted to the pressurizer level. This loop is also a testing bench for the tight high pressure apparatus. The circulating pump and the connecting flanges (Oak Ridge type) are water-tight. The feed pump and the pressure reducing valves are not; the un-tight ones have a system of leak recovery. To permanently check the tightness the circuit has been fitted with a leak detection system (similar to the HRT one). (author) [fr

  10. 24 CFR 1715.27 - Fair housing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Fair housing. 1715.27 Section 1715.27 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN...

  11. Convective transport resistance in the vitreous humor

    Science.gov (United States)

    Penkova, Anita; Sadhal, Satwindar; Ratanakijsuntorn, Komsan; Moats, Rex; Tang, Yang; Hughes, Patrick; Robinson, Michael; Lee, Susan

    2012-11-01

    It has been established by MRI visualization experiments that the convection of nanoparticles and large molecules with high rate of water flow in the vitreous humor will experience resistance, depending on the respective permeabilities of the injected solute. A set of experiments conducted with Gd-DTPA (Magnevist, Bayer AG, Leverkusen, Germany) and 30 nm gadolinium-based particles (Gado CELLTrackTM, Biopal, Worcester, MA) as MRI contrast agents showed that the degree of convective transport in this Darcy-type porous medium varies between the two solutes. These experiments consisted of injecting a mixture of the two (a 30 μl solution of 2% Magnevist and 1% nanoparticles) at the middle of the vitreous of an ex vivo whole bovine eye and subjecting the vitreous to water flow rate of 100 μl/min. The water (0.9% saline solution) was injected at the top of the eye, and was allowed to drain through small slits cut at the bottom of the eyeball. After 50 minutes of pumping, MRI images showed that the water flow carried the Gd-DTPA farther than the nanoparticles, even though the two solutes, being mixed, were subjected to the same convective flow conditions. We find that the convected solute lags the water flow, depending on the solute permeability. The usual convection term needs to be adjusted to allow for the filtration effect on the larger particles in the form (1- σ) u . ∇ c with important implications for the modeling of such systems.

  12. A simple steady state model of the distribution of vertical temperature in broiler houses without internal air circulation

    NARCIS (Netherlands)

    Beek, van G.; Beeking, F.F.E.

    1995-01-01

    1. The vertical temperature profile in a broiler house depends on several factors: ground temperature, heat production by the birds, heating of litter by resting birds, stratification and radiation, microbial heat production in the litter, moisture loss from litter and natural convection around the

  13. Integrable systems and loop coproducts

    International Nuclear Information System (INIS)

    Musso, Fabio

    2010-01-01

    We present a generalization of a framework for the construction of classical integrable systems that we call loop coproduct formulation (Musso 2010 J. Phys. A: Math. Theor. 43 434026). In this paper, the loop coproduct formulation includes systems of Gelfand-Tsetlin type, the linear r-matrix formulation, the Sklyanin algebras, the reflection algebras, the coalgebra symmetry approach and some of its generalizations as particular cases, showing that all these apparently different approaches have a common algebraic origin. On the other hand, all these subcases do not exhaust the domain of applicability of this new technique, so that new possible directions of investigation do naturally emerge in this framework.

  14. Perturbations in loop quantum cosmology

    International Nuclear Information System (INIS)

    Nelson, W; Agullo, I; Ashtekar, A

    2014-01-01

    The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the theory. For this to be possible, we need a detailed understanding of the generation and evolution of inhomogeneous perturbations during the early, quantum gravity phase of the universe. Here, we have described how Loop Quantum Cosmology provides a completion of the inflationary paradigm, that is consistent with the observed power spectra of the CMB

  15. LISA Pathfinder: OPD loop characterisation

    Science.gov (United States)

    Born, Michael; LPF Collaboration

    2017-05-01

    The optical metrology system (OMS) of the LISA Pathfinder mission is measuring the distance between two free-floating test masses with unprecedented precision. One of the four OMS heterodyne interferometers reads out the phase difference between the reference and the measurement laser beam. This phase from the reference interferometer is common to all other longitudinal interferometer read outs and therefore subtracted. In addition, the phase is fed back via the digital optical pathlength difference (OPD) control loop to keep it close to zero. Here, we analyse the loop parameters and compare them to on-ground measurement results.

  16. LOOP: engineering marvel, economic calamity

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, E B

    1985-01-01

    The Louisiana Offshore Oil Port (LOOP) is the first superport built in the Lower 48. The United States was the only major oil-importing country that did not have a superport, and therefore, could not offload very large crude carriers (VLCCs). Unfortunately, a number of factors changed after it was decided to build LOOP, and these, plus the onerous provisions of the Deepwater Ports Act of 1974, which authorized superports, prevented LOOP from operating economically. LOOP's facilities consist of an offshore platform complex with three single-point-mooring (SPM) system buoys, 19 miles offshore in 110 feet of water, as well as a 32-million-barrel storage terminal 31 miles inland at Clovelly Salt Dome, and connecting pipelines offshore and onshore. By the time LOOP was started-up in May 1981, demand for oil had declined, because of rises in the price of oil, and the source of US oil imports had shifted back to the western hemisphere, away from the eastern hemisphere, closer to the US. The refinery mix in the US also changed, because of up-grading of a number of big refineries, which further reduced demand and made heavier crudes from countries like Mexico and Venezuela more economical. Because of reduced oil imports and shorter hauls, oil shippers started using or continued to use smaller tankers. Smaller tankers are not economical for LOOP, nor do they need LOOP. The start-up of the Trans-Alaska Pipeline System (TAPS) in mid-1977 backed out 1.5 million bd/sup -1/ of foreign imports. TAPS' capacity coincides with LOOP's offloading capacity of 1.4 million bd/sup -1/. US decontrol of domestic crude in 1981 and increased drilling, plus general energy conservation further reduced US oil imports. US consumption declined to 15.1 million bd/sup -1/ in 1983, from 18.8 million bd/sup -1/ in 1978. This award-winning superport needed federal decontrol and increased oil imports along with more VLCCs, in order to operate economically.

  17. Two-Loop Splitting Amplitudes

    International Nuclear Information System (INIS)

    Bern, Z.

    2004-01-01

    Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method retains the simple factorization properties of light-cone gauge, but avoids the need for prescriptions such as the principal value or Mandelstam-Leibbrandt ones. The encountered loop momentum integrals are then evaluated using integration-by-parts and Lorentz invariance identities. We outline a variety of applications for these splitting amplitudes

  18. Two-loop splitting amplitudes

    International Nuclear Information System (INIS)

    Bern, Z.; Dixon, L.J.; Kosower, D.A.

    2004-01-01

    Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method retains the simple factorization properties of light-cone gauge, but avoids the need for prescriptions such as the principal value or Mandelstam-Leibbrandt ones. The encountered loop momentum integrals are then evaluated using integration-by-parts and Lorentz invariance identities. We outline a variety of applications for these splitting amplitudes

  19. Fermions and loops on graphs: I. Loop calculus for determinants

    International Nuclear Information System (INIS)

    Chernyak, Vladimir Y; Chertkov, Michael

    2008-01-01

    This paper is the first in a series devoted to evaluation of the partition function in statistical models on graphs with loops in terms of the Berezin/fermion integrals. The paper focuses on a representation of the determinant of a square matrix in terms of a finite series, where each term corresponds to a loop on the graph. The representation is based on a fermion version of the loop calculus, previously introduced by the authors for graphical models with finite alphabets. Our construction contains two levels. First, we represent the determinant in terms of an integral over anti-commuting Grassmann variables, with some reparametrization/gauge freedom hidden in the formulation. Second, we show that a special choice of the gauge, called the BP (Bethe–Peierls or belief propagation) gauge, yields the desired loop representation. The set of gauge fixing BP conditions is equivalent to the Gaussian BP equations, discussed in the past as efficient (linear scaling) heuristics for estimating the covariance of a sparse positive matrix

  20. Robust fault detection in open loop vs. closed loop

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.

    1997-01-01

    The robustness aspects of fault detection and isolation (FDI) for uncertain systems are considered. The FDI problem is considered in a standard problem formulation. The FDI design problem is analyzed both in the case where the control input signal is considered as a known external input signal (o...... (open loop) and when the input signal is generated by a feedback controller...

  1. A virtual closed loop method for closed loop identification

    NARCIS (Netherlands)

    Agüero, J.C.; Goodwin, G.C.; Hof, Van den P.M.J.

    2011-01-01

    Indirect methods for the identification of linear plant models on the basis of closed loop data are based on the use of (reconstructed) input signals that are uncorrelated with the noise. This generally requires exact (linear) controller knowledge. On the other hand, direct identification requires

  2. Multifamily Housing Physical Inspection Scores

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Real Estate Assessment Center conducts physical property inspections of properties that are owned, insured or subsidized by HUD, including public housing and...

  3. FEMA Housing Assistance Renters - API

    Data.gov (United States)

    Department of Homeland Security — This dataset lists aggregated, non-PII dataset of FEMA Housing Assistance Program for House Renters The data was generated by FEMA's ECIM (Enterprise Coordination...

  4. HUD Approved Housing Counseling Agencies

    Data.gov (United States)

    Department of Housing and Urban Development — HUD sponsors housing counseling agencies throughout the country that can provide advice on buying a home, renting, defaults, foreclosures, and credit issues. This...

  5. Public Housing Agency (PHA) Inventory

    Data.gov (United States)

    Department of Housing and Urban Development — The dataset contains current data on low rent and Section 8 units in PHA's administered by HUD. The Section 8 Rental Voucher Program increases affordable housing...

  6. Public Housing Physical Inspection Scores

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Real Estate Assessment Center conducts physical property inspections of properties that are owned, insured or subsidized by HUD, including public housing and...

  7. House Committee on Veterans' Affairs

    Science.gov (United States)

    ... the beaches of Normandy, from t... [...] Read Article House Doubles Down on Commitment to Veterans 08 Nov ... R-Tenn.) released the following statement after the House of Representatives passed nine veterans bills Tuesday and ...

  8. FEMA Housing Assistance Owners - API

    Data.gov (United States)

    Department of Homeland Security — This dataset lists aggregated, non-PII dataset of FEMA Housing Assistance Program for House Owners The data was generated by FEMA's ECIM (Enterprise Coordination...

  9. Risk shocks and housing markets

    OpenAIRE

    Dorofeenko, Viktor; Lee, Gabriel S.; Salyer, Kevin D.

    2010-01-01

    Abstract: This paper analyzes the role of uncertainty in a multi-sector housing model with financial frictions. We include time varying uncertainty (i.e. risk shocks) in the technology shocks that affect housing production. The analysis demonstratesthat risk shocks to the housing production sector are a quantitatively important impulse mechanism for the business cycle. Also, we demonstrate that bankruptcy costs act as an endogenous markup factor in housing prices; as a consequence, the volati...

  10. A study of the 21 March 2012 tornadic quasi linear convective system in Catalonia

    Science.gov (United States)

    Bech, Joan; Arús, Joan; Castán, Salvador; Pineda, Nicolau; Rigo, Tomeu; Montanyà, Joan; van der Velde, Oscar

    2015-05-01

    This study presents a description of a quasi linear convective system that took place in Catalonia (NE Spain) on 21 March 2012 producing heavy rainfall, moderate lightning activity and a weak tornado in the village of Ivars d'Urgell around 19 UTC after local sunset. A post-event survey indicated EF0 and EF1 damage in houses of the village - roofs and ceilings, broken windows, fences and walls and trees knocked down - along a track approximately 4 km long and about 20 m wide. Doppler radar observations show that the parent thunderstorm that spawned the tornado was one of a series that developed along a convective line that moved from S to N, initiating convective activity in terms of precipitation and lightning in the Mediterranean Sea and moving inland in S Catalonia (Tarragona and Salou coastal areas, producing local flash floods). Convective activity remained several hours with series of thunderstorms developing along the same paths. The synoptic situation was dominated by a high pressure ridge extending from northern Africa to central Europe, with a closed maximum sea level pressure area around 1036 hPa over northern France, southern Germany and Austria. On the other hand a relative low pressure area seen on 850 hPa and upper levels was present over the Iberian Peninsula, favouring a southern maritime flow from the Mediterranean between the forward part of the low pressure area and the high pressure system which blocked the advance of the low to the east. In the study we examine both the synoptic environment and storm scale observations with Doppler radar and total lightning data (cloud to ground and intracloud flashes) that lead to this cool-season severe convective event which is remarkable given the fact that, unlike in this case, most reported tornadoes in the region occur during the warm season (with peaks in August and September) and during daylight hours (6 to 18 UTC).

  11. Renovation of social housing

    DEFF Research Database (Denmark)

    Jensen, Stina Rask; Hvejsel, Marie Frier; Kirkegaard, Poul Henning

    consumption in the building sector. This planned transformation towards a more energy-efficient building mass involves changes in the building envelope and, as such, is likely to influence the experience of the built environment dramatically, both interior and exterior. Recent research shows, however...... in the renovation of social housing. Methodologically, this hypothesis is investigated by re-reading the task of energy renovation through the lens of tectonic architectural theory. Specifically, Eduard Sekler’s etymological distinction between structure, construction, and tectonics is developed as a framework...... for addressing the spatial implications and potentials of technical initiatives in contemporary energy renovations within the continuum described by Scott. The framework is applied in two case studies of recent energy renovations of social housing dwellings. Finally, the paper discusses whether the technical...

  12. Housing characteristics 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    This report, Housing Characteristics 1993, presents statistics about the energy-related characteristics of US households. These data were collected in the 1993 Residential Energy Consumption Survey (RECS) -- the ninth in a series of nationwide energy consumption surveys conducted since 1978 by the Energy Information Administration of the US Department of Energy. Over 7 thousand households were surveyed, representing 97 million households nationwide. A second report, to be released in late 1995, will present statistics on residential energy consumption and expenditures.

  13. Comparison of thermo-hydraulic analysis with measurements for HELIOS. The scaled integral test loop for PEACER

    International Nuclear Information System (INIS)

    Cho, Jae Hyun; Lim, Jun; Kim, Ji Hak; Hwang, Il Soon

    2009-01-01

    A scaled-down Lead-Bismuth Eutectic circulating integral test loop named as HELIOS (Heavy Eutectic liquid metal Loop for Integral test of Operability and Safety of PEACER) has been employed to characterize steady-state isothermal forced circulation behavior and non-isothermal natural circulation capability of the lead and lead-alloy cooled advanced nuclear energy systems (LACANES). In this time, thermal-hydraulic experiments have been carried out using HELIOS following rigorous calibration campaigns on sensors for temperature and pressure, especially isothermal steady-state forced convection using by the pump. The isothermal steady-state forced convection test was performed to obtain the pressure loss information including friction loss coefficients and form loss coefficients. Then its data were compared with multi-approaching analysis including hand calculation results and computer simulation code results. (MARS-LBE, CFX). We report the results of comparisons between the analysis and measurements together. (author)

  14. Convective mixing in helium white dwarfs

    International Nuclear Information System (INIS)

    Vauclair, G.; Fontaine, G.

    1979-01-01

    The conditions under which convective mixing episodes take place between the helium envelopes and the underlying carbon layers in helium-rich white dwarfs are investigated. It is found that, for essentially any value of the initial helium content less than the maximum mass a helium convection zone can have, mixing does occur, and leads, in the vast majority of cases, to an almost pure carbon superficial composition. Mixing products that show only traces of carbon while retaining helium-dominated envelopes are possible only if the initial helium content is quite close to the maximum possible mass of the helium convection zone. In the presence of turbulence, this restriction could be relaxed, however, and the helium-rich lambda4670 stars may possibly be explained in this fashion

  15. Literacy Mediation in Neighbourhood Houses

    Science.gov (United States)

    Thompson, Sally

    2015-01-01

    Interactions between staff in Neighbourhood Houses, and the socially and educationally disadvantaged community members who visit Neighbourhood Houses, have been viewed through many lenses, including community development, social support, caring and compassion. This paper looks at Neighbourhood Houses as sites of pedagogical practice. More…

  16. Analysis of USAREUR Family Housing.

    Science.gov (United States)

    1985-04-01

    Standard Installation/Division Personnel System SJA ................ Staff Judge Advocate SPSS ............... Statistical Package for the...for Projecting Family Housing Requirements. a. Attempts to define USAREUR’s programmable family housing deficit Sbased on the FHS have caused anguish ...responses using the Statistical Package for the Social Sciences ( SPSS ) computer program. E-2 ANNEX E RESPONSE TO ESC HOUSING QUESTIONNAIRE Section Page I

  17. Belgrade: Waning houses

    Directory of Open Access Journals (Sweden)

    Jakšić Milica

    2002-01-01

    Full Text Available In some streets of Belgrade we can still find old houses, which hold an ancient dream of dignity, comfort and beauty. They probably live their last days, staring somewhere in the distance - into foggy spaces of their forgetfulness. They stand in fragile rows, increasingly dilapidated disappearing one by one, pretty and sad in their loneliness. They fade attacked by winds, by sunshine, by rains, sorrowed by coldness of their empty rooms. We have no right to let them disappear without any remembrance, to allow them to vanish from of our lives, because - if that happens - that will make poorer both our legacy and us for the future. Thus, we must find ways to hold these old houses, to read and understand their messages, to keep the prints of their spirit and shapes. How to achieve that? If it is true that the beauty of the landscape is hidden in the eyes, which look at it, then drawing is certainly one of the modes to record the wonderful secret of these pretty old houses, silently disappearing from the urban life.

  18. The White House saga

    Directory of Open Access Journals (Sweden)

    Daković Nevena

    2015-01-01

    Full Text Available Frank Capra expressed his gratitude to the immigrant dream come true by creating a brilliant cinematic myth about the American political system, presenting it as an 'inherently good' when in the hands of honest and good people. His 'morality fairytales', 'fantasies of good will' imbued with belief in restoration of old-new principles, offer complex reflections on an idealised Americanism of the 1930s which have become the foundation of representations of the American political system. The Capraesque narrative - 'a blend of optimism, humor, patriotism, and, to those who really understand his work, (and darkness, despair, and the need to fight for things you care about...' (Bassinger 1982: 48 - as a combination of all-American values, ordinary people and historical figures, a democracy myth - has been extended by an endless network of intertextual echoes in film and TV production. Following the developmental lines - through political melodrama, melodramatic politics and political soap opera - one will be led from Capra to the series The West Wing (1996 - 2006, House of Cards (2013 - 2015 and Madame Secretary (2014 - ; from the comprehensive Washington Postcard (Mr. Smith Goes to Washington, 1939 to the focal points at the White House; from Capra's comedy to the saga of the fight against terrorism led by the president and both ordinary and trained American citizens (White House Down, 2013, Roland Emmerich.

  19. Radionuclides in house dust

    Energy Technology Data Exchange (ETDEWEB)

    Fry, F A; Green, N; Dodd, N J; Hammond, D J

    1985-04-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  20. Free loop spaces and cyclohedra

    Czech Academy of Sciences Publication Activity Database

    Markl, Martin

    2003-01-01

    Roč. 71, - (2003), s. 151-157 R&D Projects: GA AV ČR IAA1019203 Institutional research plan: CEZ:AV0Z1019905; CEZ:AV0Z1019905 Keywords : cyclohedron * free loop space * recognition Subject RIV: BA - General Mathematics

  1. Feedback - closing the loop digitally

    International Nuclear Information System (INIS)

    Zagel, J.; Chase, B.

    1992-01-01

    Many feedback and feedforward systems are now using microprocessors within the loop. We describe the wide range of possibilities and problems that arise. We also propose some ideas for analysis and testing, including examples of motion control in the Flying Wire systems in Main Ring and Tevatron and Low Level RF control now being built for the Fermilab Linac upgrade. (author)

  2. Morbidity of temporary loop ileostomies

    NARCIS (Netherlands)

    Bakx, R.; Busch, O. R. C.; Bemelman, W. A.; Veldink, G. J.; Slors, J. F. M.; van Lanschot, J. J. B.

    2004-01-01

    Background/Aims: A temporary loop ileostomy is constructed to protect a distal colonic anastomosis. Closure is usually performed not earlier than 8 - 12 weeks after the primary operation. During this period, stoma-related complications can occur and enhance the adverse effect on quality of life. The

  3. Wilson loops in Kerr gravitation

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

    1981-01-01

    The ordered integrals for several paths in Kerr gravitation is computed in a compact form. When the path is closed its relation with the angular parallel displacement is discussed and the corresponding Wilson loop is calculated. The validity of Mandelstam relations for gauge fields is also explicitly verified. (Author) [pt

  4. Loop quantum cosmology: Recent progress

    Indian Academy of Sciences (India)

    Aspects of the full theory of loop quantum gravity can be studied in a simpler .... group) 1-forms and vector fields and Λ is an SO(3)-matrix indicating the internal ... are p and c which are related to the more familiar scale factor by the relations.

  5. Loop quantum cosmology and singularities.

    Science.gov (United States)

    Struyve, Ward

    2017-08-15

    Loop quantum gravity is believed to eliminate singularities such as the big bang and big crunch singularity. This belief is based on studies of so-called loop quantum cosmology which concerns symmetry-reduced models of quantum gravity. In this paper, the problem of singularities is analysed in the context of the Bohmian formulation of loop quantum cosmology. In this formulation there is an actual metric in addition to the wave function, which evolves stochastically (rather than deterministically as the case of the particle evolution in non-relativistic Bohmian mechanics). Thus a singularity occurs whenever this actual metric is singular. It is shown that in the loop quantum cosmology for a homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker space-time with arbitrary constant spatial curvature and cosmological constant, coupled to a massless homogeneous scalar field, a big bang or big crunch singularity is never obtained. This should be contrasted with the fact that in the Bohmian formulation of the Wheeler-DeWitt theory singularities may exist.

  6. Independent SU(2)-loop variables

    International Nuclear Information System (INIS)

    Loll, R.

    1991-04-01

    We give a reduction procedure for SU(2)-trace variables and introduce a complete set of indepentent, gauge-invariant and almost local loop variables for the configuration space of SU(2)-lattice gauge theory in 2+1 dimensions. (orig.)

  7. An experimental study of dislocation loop nucleation

    International Nuclear Information System (INIS)

    Bounaud, J.Y.; Leteurtre, J.

    1975-01-01

    The nucleation of dislocation loops is experimentally studied by observing the demixion of the Burgers vectors of dislocation loops nucleated in copper whiskers irradiated in flexion by fission fragments at room temperature. The demixion of Burgers vectors is observed by the dimensional effects of dislocation loops: after irradiation, the applied stress is removed; the whisker shows a residual strain that is due to loops because, after an annealing treatment to evaporate dislocation loops, each whisker recovers its initial straight shape. Everywhere along the whisker, the radius of curvature is measured and plotted vs the max. applied stress. Estimations of the interstitial and vacancy dislocation loop nuclei are derived [fr

  8. Natural Convective Heat Transfer from Narrow Plates

    CERN Document Server

    Oosthuizen, Patrick H

    2013-01-01

    Natural Convective Heat Transfer from Narrow Plates deals with a heat transfer situation that is of significant practical importance but which is not adequately dealt with in any existing textbooks or in any widely available review papers. The aim of the book is to introduce the reader to recent studies of natural convection from narrow plates including the effects of plate edge conditions, plate inclination, thermal conditions at the plate surface and interaction of the flows over adjacent plates. Both numerical and experimental studies are discussed and correlation equations based on the results of these studies are reviewed.

  9. Introductory analysis of Benard-Marangoni convection

    International Nuclear Information System (INIS)

    Maroto, J A; Perez-Munuzuri, V; Romero-Cano, M S

    2007-01-01

    We describe experiments on Benard-Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Benard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and introductory analysis which has the additional advantage of providing very suggestive experiments. As a consequence, we recommend our device for use as a laboratory experiment for undergraduate students of the thermodynamics of nonlinear and fluid physics

  10. Might electrical earthing affect convection of light

    International Nuclear Information System (INIS)

    Budrikis, Z.L.

    1982-01-01

    Partial convection of light by moving media was predicted by Fresnel and verified by Fizeau, Zeeman and others. It is accepted as an important argument in favour of the Special Theory of Relativity. The suggestion is made here that the convection is partial only when the propagating medium is moved with respect to its electrically earthed surroundings and that it would be total if an earthed shield was co-moving with the medium. This is based on a reinterpretation of Maxwell's equations wherein they are seen as macroscopic relationships that are in each case valid only in respect of a particular inertial frame of reference, the local electrical earth frame. (Auth.)

  11. Introductory analysis of Benard-Marangoni convection

    Energy Technology Data Exchange (ETDEWEB)

    Maroto, J A [Group of Physics and Chemistry of Linares, Escuela Politecnica Superior, St Alfonso X El Sabio, 28, University of Jaen, E-23700 Linares, Jaen (Spain); Perez-Munuzuri, V [Group of Nonlinear Physics, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Romero-Cano, M S [Group of Complex Fluids Physics, Department of Applied Physics, University of Almeria, E-04120 Almeria (Spain)

    2007-03-15

    We describe experiments on Benard-Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Benard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and introductory analysis which has the additional advantage of providing very suggestive experiments. As a consequence, we recommend our device for use as a laboratory experiment for undergraduate students of the thermodynamics of nonlinear and fluid physics.

  12. Lattice BGK simulation of natural convection

    International Nuclear Information System (INIS)

    Chen, Yu; Ohashi, Hirotada; Akiyama, Mamoru

    1995-01-01

    Recently a new thermal lattice Bhatnagar-Gross-Krook fluid model was suggested by the authors. In this study, this new model was applied into the numerical simulation of natural convection, namely the Rayleigh Benard flow. The critical number for the onset of convective phenomenon was numerically measured and compared with that of theoretical prediction. A gravity dependent deviation was found in the numerical simulation, which is explained as an unavoidable consequence of the incorporation of gravity force in the lattice BGK system. (author)

  13. Mental health and housing.

    Science.gov (United States)

    Kari-Koskinen, O; Karvonen, P

    1976-01-01

    With the present trend away from the designing of individual buildings and towards the systematic planning of whole residential communities, it should be possible to take mental health requirements into account at the planning stage. At present, sociologists are all too seldom consulted on matters of residential planning. When discussing the relationship between housing and mental health one cannot restrict oneself only to the external aspects of the house, but rather one must also consider the opportunities available for the members of the family to satisfy their own needs, both within the home and in its immediate surroundings. Factors which may affect residential requirements include geographical location, type and standard of dwelling and time and continuity of occupation. A move between two districts or groups representing different housing norms and values may lead to withdrawal symptoms in the individual. This may arise equally well from the remoteness of the country districts as from the conflicting pressures brought on by the abundance of contacts available in the large towns. Town life tends to heighten susceptibility to neuroses and personality conflicts. The character of a residential area may affect the mental health of its occupants. Faris & Dunham (4), in studying the incidence of various types of mental illness with an urban population, observed that schizophrenia was most common among people who were in some way isolated from social involvement. The striving for spaciousness in residential areas and the creation of a "summer city" or "garden city" image or a "family-centred way of life" may lead to unexpected problems and have a variety of social consequences. Mental health difficulties have been noted, for example, among housewives in "dormitory" towns or suburbs (11). The institutions required by a community may be grouped into four categories, representing the basic needs of its members. These are (1) economic institutions, (2) social and

  14. Evaluation of an assisted convection system for integrated reactors

    International Nuclear Information System (INIS)

    Patruno, Luciano

    2006-01-01

    This work consists of the analyze of changing to an assisted convection system the CAREM-25 nuclear power plant design.The work is focused on the design, construction and measurement of an experimental hydraulic loop which contains a jet pump.There is also a characterization of parameters such as flow rate, hydrostatic pressure, efficiency, velocity profiles and development length using different tools such as theoretical formulations, numeric simulations and experimental data. New set points are found in CAREM thermo hydraulic parameters which take the thermal power to up to 150MW, and the water flow rate to 615 kg/s.To achieve this goals, the use of twelve jet pumps is proposed at a flow rate coefficient of 10.The results on the static pressure provided by the jet pump are calculated theoretically and compared with experimental data.There is an extrapolation of the results to higher flow rate values to be applied to the CAREM-25 design.Concerning the experimental work, the results show a good match on flow rate between the measured data and the theoretical results.There is a reasonable match in the coefficient of flow rate (M), even when the measurement uncertainties are quite high (about 13 %).It is also shown an efficiency measurement, which is up to 14 % [es

  15. Comparing convective heat fluxes derived from thermodynamics to a radiative-convective model and GCMs

    Science.gov (United States)

    Dhara, Chirag; Renner, Maik; Kleidon, Axel

    2015-04-01

    The convective transport of heat and moisture plays a key role in the climate system, but the transport is typically parameterized in models. Here, we aim at the simplest possible physical representation and treat convective heat fluxes as the result of a heat engine. We combine the well-known Carnot limit of this heat engine with the energy balances of the surface-atmosphere system that describe how the temperature difference is affected by convective heat transport, yielding a maximum power limit of convection. This results in a simple analytic expression for convective strength that depends primarily on surface solar absorption. We compare this expression with an idealized grey atmosphere radiative-convective (RC) model as well as Global Circulation Model (GCM) simulations at the grid scale. We find that our simple expression as well as the RC model can explain much of the geographic variation of the GCM output, resulting in strong linear correlations among the three approaches. The RC model, however, shows a lower bias than our simple expression. We identify the use of the prescribed convective adjustment in RC-like models as the reason for the lower bias. The strength of our model lies in its ability to capture the geographic variation of convective strength with a parameter-free expression. On the other hand, the comparison with the RC model indicates a method for improving the formulation of radiative transfer in our simple approach. We also find that the latent heat fluxes compare very well among the approaches, as well as their sensitivity to surface warming. What our comparison suggests is that the strength of convection and their sensitivity in the climatic mean can be estimated relatively robustly by rather simple approaches.

  16. Transient boiling in two-phase helium natural circulation loops

    Science.gov (United States)

    Furci, H.; Baudouy, B.; Four, A.; Meuris, C.

    2014-01-01

    Two-phase helium natural circulation loops are used for cooling large superconducting magnets, as CMS for LHC. During normal operation or in the case of incidents, transients are exerted on the cooling system. Here a cooling system of this type is studied experimentally. Sudden power changes are operated on a vertical-heated-section natural convection loop, simulating a fast increase of heat deposition on magnet cooling pipes. Mass flow rate, heated section wall temperature and pressure drop variations are measured as a function of time, to assess the time behavior concerning the boiling regime according to the values of power injected on the heated section. The boiling curves and critical heat flux (CHF) values have been obtained in steady state. Temperature evolution has been observed in order to explore the operating ranges where heat transfer is deteriorated. Premature film boiling has been observed during transients on the heated section in some power ranges, even at appreciably lower values than the CHF. A way of attenuating these undesired temperature excursions has been identified through the application of high enough initial heating power.

  17. House Prices and Public Debt

    DEFF Research Database (Denmark)

    Gjedsted Nielsen, Mads; Rzeznik, Aleksandra

    By using the 2002 case of fraud in the Danish municipality Farum by then mayor Peter Brixtofte as an exogenous shock to public debt of 1 billion DKK, I estimate the effect of public debt on house prices. I find that the average home ownership lost about 570,000 DKK or as much as 29% of the average...... house price in the municipality. Furthermore, I document that the aggregate house price loss of 2.1 billion DKK greatly exceeds the increase in public debt of 1 billion DKK. I find that the drop in house prices is sustained 1 year, indicating that the housing market initially overreacts...

  18. 24 CFR 982.617 - Shared housing: Rent and voucher housing assistance payment.

    Science.gov (United States)

    2010-04-01

    ... Special Housing Types Shared Housing § 982.617 Shared housing: Rent and voucher housing assistance payment... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Shared housing: Rent and voucher housing assistance payment. 982.617 Section 982.617 Housing and Urban Development Regulations Relating to...

  19. Is Housing a Health Insult?

    Science.gov (United States)

    Baker, Emma; Beer, Andrew; Lester, Laurence; Pevalin, David; Whitehead, Christine; Bentley, Rebecca

    2017-05-26

    In seeking to understand the relationship between housing and health, research attention is often focussed on separate components of people's whole housing 'bundles'. We propose in this paper that such conceptual and methodological abstraction of elements of the housing and health relationship limits our ability to understand the scale of the accumulated effect of housing on health and thereby contributes to the under-recognition of adequate housing as a social policy tool and powerful health intervention. In this paper, we propose and describe an index to capture the means by which housing bundles influence health. We conceptualise the index as reflecting accumulated housing 'insults to health'-an Index of Housing Insults (IHI). We apply the index to a sample of 1000 low-income households in Australia. The analysis shows a graded association between housing insults and health on all outcome measures. Further, after controlling for possible confounders, the IHI is shown to provide additional predictive power to the explanation of levels of mental health, general health and clinical depression beyond more traditional proxy measures. Overall, this paper reinforces the need to look not just at separate housing components but to embrace a broader understanding of the relationship between housing and health.

  20. Environmental Health Disparities in Housing

    Science.gov (United States)

    2011-01-01

    The physical infrastructure and housing make human interaction possible and provide shelter. How well that infrastructure performs and which groups it serves have important implications for social equity and health. Populations in inadequate housing are more likely to have environmental diseases and injuries. Substantial disparities in housing have remained largely unchanged. Approximately 2.6 million (7.5%) non-Hispanic Blacks and 5.9 million Whites (2.8%) live in substandard housing. Segregation, lack of housing mobility, and homelessness are all associated with adverse health outcomes. Yet the experience with childhood lead poisoning in the United States has shown that housing-related disparities can be reduced. Effective interventions should be implemented to reduce environmental health disparities related to housing. PMID:21551378

  1. High Ra, high Pr convection with viscosity gradients

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. High Ra, high Pr convection with viscosity gradients. Weak upward flow through mesh. Top fluid more viscous. Unstable layer Instability Convection.

  2. Stretched flow of Carreau nanofluid with convective boundary ...

    Indian Academy of Sciences (India)

    journal of. January 2016 physics pp. 3–17. Stretched flow of Carreau nanofluid with ... fluid over a flat plate subjected to convective surface condition. ... the steady laminar boundary layer flow over a permeable plate with a convective boundary.

  3. Two- and three-loop amplitudes in covariant loop calculus

    International Nuclear Information System (INIS)

    Roland, K.

    1988-04-01

    We study 2- and 3-loop vacuum-amplitudes for the closed bosonic string. We compare two sets of expressions for the corresponding density on moduli space: One, based on the covariant Reggeon loop calculus (where modular invariance is not manifest). The other, based on analytic geometry. We want to prove identity between the two sets of expressions. Quite apart from demonstrating modular invariance of the Reggeon results, this would in itself be a remarkable mathematical feature. Identity is established to 'high' order in some moduli and exactly in others. The expansions reveal an essentially number-theoretical structure. Agreement is found only by exploiting the connection between the 4 Jacobi θ-functions and number theory. (orig.)

  4. Two- and three-loop amplitudes in covariant loop calculus

    International Nuclear Information System (INIS)

    Roland, K.

    1989-01-01

    We study two- and three-loop vacuum amplitudes for the closed bosonic string. We compare two sets of expressions for the corresponding density on moduli space. One is based on the covariant reggeon loop calculus (where modular invariance is not manifest). The other is based on analytic geometry. We want to prove identity between the two sets of expressions. Quite apart from demonstrating modular invariance of the reggeon results, this would in itself be a remarkable mathematical feature. Identity is established to ''high'' order in some moduli and exactly in others. The expansions reveal an essentially number-theoretic structure. Agreement is found only by exploiting the connection between the four Jacobi θ-functions and number theory. (orig.)

  5. Picophytoplankton variability: Influence of winter convective mixing and advection in the northeastern Arabian Sea

    Science.gov (United States)

    Bemal, Suchandan; Anil, Arga Chandrashekar; Shankar, D.; Remya, R.; Roy, Rajdeep

    2018-04-01

    The deepening of mixed layer and ensuing changes in optical and physicochemical properties of euphotic zone can influence phytoplankton community dynamics in the northeastern Arabian Sea during winter monsoon. The response of picophytoplankton community to such changes during winter convective mixing is not well understood. Herein, we have compared variations in the picophytoplankton community structure during early (November-December 2012), peak (end-January 2014) and late (mid-February 2015) winter monsoon from three separate cruises in the southern northeastern Arabian Sea. The higher Synechococcus abundance owing to entrainment of nutrients in mixed layer was observed during peak winter monsoon, while the concomitant changes in nitrate concentration, light and oxygen environment restricted Prochlorococcus growth resulting in lower abundance during the same period. This highlights the diverse responses of picophytoplankton groups to physicochemical changes of water column during winter convective mixing. The divinyl chlorophyll b/a ratio (marker for Prochlorococcus ecotypes) indicated prevalence of one low-light adapted ecotype (sensitive to light shock) in sub-surface water, one high-light adapted ecotype in surface water during early winter monsoon and both disappeared during intense mixing period in peak winter monsoon. Subsequently, a distinct low-light adapted ecotype, capable to tolerate light shock, was noticed during late winter monsoon and we argue that this ecotype is introduced to southern northeastern Arabian Sea through advection from north by sub-surface circulation. The total picophytoplankton biomass available to microbial loop is restored during late winter monsoon, when stratification begins, with a higher abundance of Synechococcus and the re-occurrence of Prochlorococcus population in the region. These inferences indicate that variability in picophytoplankton community structure and their contribution to the microbial loop are driven by

  6. Flow loop studies with AMAX coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Wildman, D.J.; Ekmann, J.M.

    1984-03-01

    The coal-water mixtures (CWM) with a stabilizer and the CWM without stabilizers were successfully transported through a flow loop facility under a variety of conditions. The handling characteristics of both CWM were reasonable. The mix tank mixer was not needed during nontesting hours to prevent settling of either material. After several days of transporting the nonstabilized material in the loop facility, the viscosity-reducing agent became ineffective. It was necessary to increase the concentration of the viscosity-reducing agent. The material with stabilizer could not be transported through the loop facility at mass flow rates greater than 209 lb/min until overnight shearing of the CWM in the tank. The CWM without a stabilizer appeared to be slightly shear-thickening, whereas the stabilized CWM initially exhibited shear-thinning behavior. The pressure losses measured for the nonstabilized material were similar to the pressure losses measured for CWM prepared at PETC with three or four percent higher concentration of Pittsburgh seam coal. Tests performed with the stabilized CWM experienced pressure losses similar to CWM prepared at PETC with Pittsburgh seam coal of five to seven percent higher concentration. Tests 1A, 2A, 1B, and 2B were not included in the comparison of in-house-prepared CWM due to differences in pretest handling procedures. 1 figure, 2 tables.

  7. An infinite-dimensional model of free convection

    Energy Technology Data Exchange (ETDEWEB)

    Iudovich, V.I. (Rostovskii Gosudarstvennyi Universitet, Rostov-on-Don (USSR))

    1990-12-01

    An infinite-dimensional model is derived from the equations of free convection in the Boussinesq-Oberbeck approximation. The velocity field is approximated by a single mode, while the heat-conduction equation is conserved fully. It is shown that, for all supercritical Rayleigh numbers, there exist exactly two secondary convective regimes. The case of ideal convection with zero viscosity and thermal conductivity is examined. The averaging method is used to study convection regimes at high Reynolds numbers. 10 refs.

  8. Education: DNA replication using microscale natural convection.

    Science.gov (United States)

    Priye, Aashish; Hassan, Yassin A; Ugaz, Victor M

    2012-12-07

    There is a need for innovative educational experiences that unify and reinforce fundamental principles at the interface between the physical, chemical, and life sciences. These experiences empower and excite students by helping them recognize how interdisciplinary knowledge can be applied to develop new products and technologies that benefit society. Microfluidics offers an incredibly versatile tool to address this need. Here we describe our efforts to create innovative hands-on activities that introduce chemical engineering students to molecular biology by challenging them to harness microscale natural convection phenomena to perform DNA replication via the polymerase chain reaction (PCR). Experimentally, we have constructed convective PCR stations incorporating a simple design for loading and mounting cylindrical microfluidic reactors between independently controlled thermal plates. A portable motion analysis microscope enables flow patterns inside the convective reactors to be directly visualized using fluorescent bead tracers. We have also developed a hands-on computational fluid dynamics (CFD) exercise based on modeling microscale thermal convection to identify optimal geometries for DNA replication. A cognitive assessment reveals that these activities strongly impact student learning in a positive way.

  9. Evolution of Excited Convective Cells in Plasmas

    DEFF Research Database (Denmark)

    Pécseli, Hans; Juul Rasmussen, Jens; Sugai, H.

    1984-01-01

    Convective cells are excited externally in a fully ionized magnetized plasma and their space-time evolution is investigated by two-dimensional potential measurements. A positive cell is excited externally by control of the end losses in the 'scrape off' layer of a plasma column produced by surface...

  10. Free convection film flows and heat transfer

    CERN Document Server

    Shang, Deyi

    2010-01-01

    Presents development of systematic studies for hydrodynamics and heat and mass transfer in laminar free convection, accelerating film boiling and condensation of Newtonian fluids, and accelerating film flow of non-Newtonian power-law fluids. This book provides a system of analysis models with a developed velocity component method.

  11. Penetrative convection at high Rayleigh numbers

    Science.gov (United States)

    Toppaladoddi, Srikanth; Wettlaufer, John S.

    2018-04-01

    We study penetrative convection of a fluid confined between two horizontal plates, the temperatures of which are such that a temperature of maximum density lies between them. The range of Rayleigh numbers studied is Ra=[0.01 ,4 ]106,108 and the Prandtl numbers are Pr=1 and 11.6. An evolution equation for the growth of the convecting region is obtained through an integral energy balance. We identify a new nondimensional parameter, Λ , which is the ratio of temperature difference between the stable and unstable regions of the flow; larger values of Λ denote increased stability of the upper stable layer. We study the effects of Λ on the flow field using well-resolved lattice Boltzmann simulations and show that the characteristics of the flow depend sensitively upon it. For the range Λ = , we find that for a fixed Ra the Nusselt number, Nu, increases with decreasing Λ . We also investigate the effects of Λ on the vertical variation of convective heat flux and the Brunt-Väisälä frequency. Our results clearly indicate that in the limit Λ →0 the problem reduces to that of the classical Rayleigh-Bénard convection.

  12. Radiative-convective equilibrium model intercomparison project

    Science.gov (United States)

    Wing, Allison A.; Reed, Kevin A.; Satoh, Masaki; Stevens, Bjorn; Bony, Sandrine; Ohno, Tomoki

    2018-03-01

    RCEMIP, an intercomparison of multiple types of models configured in radiative-convective equilibrium (RCE), is proposed. RCE is an idealization of the climate system in which there is a balance between radiative cooling of the atmosphere and heating by convection. The scientific objectives of RCEMIP are three-fold. First, clouds and climate sensitivity will be investigated in the RCE setting. This includes determining how cloud fraction changes with warming and the role of self-aggregation of convection in climate sensitivity. Second, RCEMIP will quantify the dependence of the degree of convective aggregation and tropical circulation regimes on temperature. Finally, by providing a common baseline, RCEMIP will allow the robustness of the RCE state across the spectrum of models to be assessed, which is essential for interpreting the results found regarding clouds, climate sensitivity, and aggregation, and more generally, determining which features of tropical climate a RCE framework is useful for. A novel aspect and major advantage of RCEMIP is the accessibility of the RCE framework to a variety of models, including cloud-resolving models, general circulation models, global cloud-resolving models, single-column models, and large-eddy simulation models.

  13. Vortex statistics in turbulent rotating convection

    NARCIS (Netherlands)

    Kunnen, R.P.J.; Clercx, H.J.H.; Geurts, B.J.

    2010-01-01

    The vortices emerging in rotating turbulent Rayleigh-Bénard convection in water at Rayleigh number Ra=6.0×108 are investigated using stereoscopic particle image velocimetry and by direct numerical simulation. The so-called Q criterion is used to detect the vortices from velocity fields. This

  14. Phenomenology of convection-parameterization closure

    Directory of Open Access Journals (Sweden)

    J.-I. Yano

    2013-04-01

    Full Text Available Closure is a problem of defining the convective intensity in a given parameterization. In spite of many years of efforts and progress, it is still considered an overall unresolved problem. The present article reviews this problem from phenomenological perspectives. The physical variables that may contribute in defining the convective intensity are listed, and their statistical significances identified by observational data analyses are reviewed. A possibility is discussed for identifying a correct closure hypothesis by performing a linear stability analysis of tropical convectively coupled waves with various different closure hypotheses. Various individual theoretical issues are considered from various different perspectives. The review also emphasizes that the dominant physical factors controlling convection differ between the tropics and extra-tropics, as well as between oceanic and land areas. Both observational as well as theoretical analyses, often focused on the tropics, do not necessarily lead to conclusions consistent with our operational experiences focused on midlatitudes. Though we emphasize the importance of the interplays between these observational, theoretical and operational perspectives, we also face challenges for establishing a solid research framework that is universally applicable. An energy cycle framework is suggested as such a candidate.

  15. Oscillatory Convection in Rotating Liquid Metals

    Science.gov (United States)

    Bertin, Vincent; Grannan, Alex; Aurnou, Jonathan

    2016-11-01

    We have performed laboratory experiments in a aspect ratio Γ = 2 cylinder using liquid gallium (Pr = 0 . 023) as the working fluid. The Ekman number varies from E = 4 ×10-5 to 4 ×10-6 and the Rayleigh number varies from Ra = 3 ×105 to 2 ×107 . Using heat transfer and temperature measurements within the fluid, we characterize the different styles of low Pr rotating convective flow. The convection threshold is first overcome in the form of a container scale inertial oscillatory mode. At stronger forcing, wall-localized modes develop, coexisting with the inertial oscillatory modes in the bulk. When the strength of the buoyancy increases further, the bulk flow becomes turbulent while the wall modes remain. Our results imply that rotating convective flows in liquid metals do not develop in the form of quasi-steady columns, as in Pr = 1 planetary and stellar dynamo models, but in the form of oscillatory motions. Therefore, convection driven dynamo action in low Pr fluids can differ substantively than that occurring in typical Pr = 1 numerical models. Our results also suggest that low wavenumber, wall modes may be dynamically and observationally important in liquid metal dynamo systems. We thank the NSF Geophysics Program for support of this project.

  16. Natural convection in horizontal fluid layers

    International Nuclear Information System (INIS)

    Suo-Antilla, A.J.

    1977-02-01

    The experimental work includes developing and using a thermal convection cell to obtain measurements of the heat flux and turbulent core temperature of a horizontal layer of fluid heated internally and subject to both stabilizing and destabilizing temperature differences. The ranges of Rayleigh numbers tested were 10 7 equal to or less than R/sub I/ equal to or less than 10 13 and -10 10 equal to or less than R/sub E/ equal to or less than 10 10 . Power integral methods were found to be adequate for interpolating and extrapolating the data. The theoretical work consists of the derivation, solution and use of the mean field equations for study of thermally driven convection in horizontal layers of infinite extent. The equations were derived by a separation of variables technique where the horizontal directions were described by periodic structures and the vertical being some function of z. The derivation resulted in a coupled set of momentum and energy equations. The equations were simplified by using the infinite Prandtl number limit and neglecting direct intermodal interaction. Solutions to these equations are used to predict the existence of multi-wavenumber flows at all supercritical Rayleigh numbers. Subsequent inspection of existing experimental photographs of convecting fluids confirms their existence. The onset of time dependence is found to coincide with the onset of the second convective mode. Each mode is found to consist of two wavenumbers and typically the velocity and temperature fields of the right modal branch are found to be out of phase

  17. Unstable mixed convective transport in groundwater

    International Nuclear Information System (INIS)

    Schincariol, R.A.; Schwartz, F.W.

    1990-01-01

    This study is an experimental investigation of variable density groundwater flow in homogeneous and lenticular porous media. A solution of 500 mg/l Rhodamine WT dye served as the carrier for various concentrations of solute (NaCl) introduced into a two-dimensional flow tank at concentrations ranging from 1000 to 100,000 mg/l. At the scale of the experiments, mass transport depends upon both forced and free convection. In addition, density differences as low as 0.008 g/cm 3 (1000 mg/l NaCl) between a plume of dense water and ambient groundwater in homogeneous medium produces gravitational instabilities at realistic groundwater velocities. These instabilities are manifest by lobe-shaped protuberances that formed first along the bottom edge of the plume and later within the plume. As the density difference increases to 0.0015 g/cm 3 (2000 mg/l NaCl), 0.0037 g/cm 3 (5000 mg/l NaCl) or higher, this unstable mixing due to convective dispersion significantly alters the spreading process, resulting in a large degree of vertical spreading of the plume. In a lenticular medium the combination of convective dispersion and nonuniform flow due to heterogeneities results in relatively large dispersion. Scale considerations indicate that convective dispersion may provide an important component of mixing at the field scale. (Author) (30 refs., 12 figs., 3 tabs.)

  18. Solar Hot Water Heating by Natural Convection.

    Science.gov (United States)

    Noble, Richard D.

    1983-01-01

    Presents an undergraduate laboratory experiment in which a solar collector is used to heat water for domestic use. The working fluid is moved by natural convection so no pumps are required. Experimental apparatus is simple in design and operation so that data can be collected quickly and easily. (Author/JN)

  19. A 'backward' free-convective boundary layer

    NARCIS (Netherlands)

    Kuiken, H.K.

    1981-01-01

    In this paper the cooling of a low-heat-resistance sheet that moves downwards is considered. The free-convective velocities are assumed to be much larger than the velocity of the sheet. As a result the motion of the fluid is mainly towards the point where the sheet enters the system and a ‘backward’

  20. Natural convection inside an irregular porous cavity

    International Nuclear Information System (INIS)

    Beltran, Jorge I. LLagostera; Trevisan, Osvair Vidal

    1990-01-01

    Natural convection flow induced by heating from below in a irregular porous cavity is investigated numerically. The influence of the modified Rayleigh number and geometric ratios on heat transfer and fluid flow is studied. Global and local Nusselt for Rayleigh numbers covering the range 0 - 1600 and for several geometric ratios. The fluid flow and the temperature field are illustrated by contour maps. (author)

  1. Convection in Slab and Spheroidal Geometries

    Science.gov (United States)

    Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

    2000-01-01

    Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

  2. Preserving Symmetry in Convection-Diffusion Schemes

    NARCIS (Netherlands)

    Verstappen, R.W.C.P.; Veldman, A.E.P.; Drikakis, D.; Geurts, B.J.

    2002-01-01

    We propose to perform turbulent flow simulations in such manner that the difference operators do have the same symmetry properties as the corresponding differential operators. That is, the convective operator is represented by a skew-symmetric difference operator and the diffusive operator is

  3. Theories for convection in stellar atmospheres

    International Nuclear Information System (INIS)

    Nordlund, Aa.

    1976-02-01

    A discussion of the fundamental differences between laboratory convection in a stellar atmosphere is presented. The shortcomings of laterally homogeneous model atmospheres are analysed, and the extent to which these shortcoming are avoided in the two-component representation is discussed. Finally a qualitative discussion on the scaling properties of stellar granulation is presented. (Auth.)

  4. Terminal project heat convection in thin cylinders

    International Nuclear Information System (INIS)

    Morales Corona, J.

    1992-01-01

    Heat convection in thin cylinders and analysis about natural convection for straight vertical plates, and straight vertical cylinders submersed in a fluid are presented some works carry out by different authors in the field of heat transfer. In the part of conduction, deduction of the equation of heat conduction in cylindrical coordinates by means of energy balance in a control volume is presented. Enthalpy and internal energy are used for the outlining of the equation and finally the equation in its vectorial form is obtained. In the convection part development to calculate the Nusselt number for a straight vertical plate by a forces analysis, an energy balance and mass conservation over a control volume is outlined. Several empiric correlations to calculate the Nusselt number and its relations with other dimensionless numbers are presented. In the experimental part the way in which a prototype rode is assembled is presented measurements of temperatures attained in steady state and in free convection for working fluids as air and water are showed in tables. Also graphs of Nusselt numbers obtained in the experimental way through some empiric correlations are showed (Author)

  5. Social House Refurbishment

    OpenAIRE

    DONET CLIMENT, MARIA

    2012-01-01

    The building is located in urban Horsens on CHR. M. Østergaardsvej. Originally it was designed as part of a bigger social housing project and executed in 1956 by architect J. Broch Christensen. The project consisted of 7 very similar blocks but we are mainly focusing on block 6. The original design of the buildings was a traditional danish design with external bricks and roof tiles - all in red. Inside, the apartments were quite typical of that time. Our concept for the new building is to m...

  6. Influence of convective conditions on three dimensional mixed convective hydromagnetic boundary layer flow of Casson nanofluid

    Energy Technology Data Exchange (ETDEWEB)

    Rauf, A., E-mail: raufamar@ciitsahiwal.edu.pk [Department of Mathematics, Comsats Institute of Information Technology, Sahiwal 57000 (Pakistan); Siddiq, M.K. [Centre for Advanced Studies in Pure and Applied Mathematics, Department of Mathematics, Bahauddin Zakariya University, Multan 63000 (Pakistan); Abbasi, F.M. [Department of Mathematics, Comsats Institute of Information Technology, Islamabad 44000 (Pakistan); Meraj, M.A. [Department of Mathematics, Comsats Institute of Information Technology, Sahiwal 57000 (Pakistan); Ashraf, M. [Centre for Advanced Studies in Pure and Applied Mathematics, Department of Mathematics, Bahauddin Zakariya University, Multan 63000 (Pakistan); Shehzad, S.A. [Department of Mathematics, Comsats Institute of Information Technology, Sahiwal 57000 (Pakistan)

    2016-10-15

    The present work deals with the steady laminar three-dimensional mixed convective magnetohydrodynamic (MHD) boundary layer flow of Casson nanofluid over a bidirectional stretching surface. A uniform magnetic field is applied normal to the flow direction. Similarity variables are implemented to convert the non-linear partial differential equations into ordinary ones. Convective boundary conditions are utilized at surface of the sheet. A numerical technique of Runge–Kutta–Fehlberg (RFK45) is used to obtain the results of velocity, temperature and concentration fields. The physical dimensionless parameters are discussed through tables and graphs. - Highlights: • Mixed convective boundary layer flow of Casson nanofluid is taken into account. • Impact of magnetic field is examined. • Convective heat and mass conditions are imposed. • Numerical solutions are presented and discussed.

  7. Testing particle filters on convective scale dynamics

    Science.gov (United States)

    Haslehner, Mylene; Craig, George. C.; Janjic, Tijana

    2014-05-01

    Particle filters have been developed in recent years to deal with highly nonlinear dynamics and non Gaussian error statistics that also characterize data assimilation on convective scales. In this work we explore the use of the efficient particle filter (P.v. Leeuwen, 2011) for convective scale data assimilation application. The method is tested in idealized setting, on two stochastic models. The models were designed to reproduce some of the properties of convection, for example the rapid development and decay of convective clouds. The first model is a simple one-dimensional, discrete state birth-death model of clouds (Craig and Würsch, 2012). For this model, the efficient particle filter that includes nudging the variables shows significant improvement compared to Ensemble Kalman Filter and Sequential Importance Resampling (SIR) particle filter. The success of the combination of nudging and resampling, measured as RMS error with respect to the 'true state', is proportional to the nudging intensity. Significantly, even a very weak nudging intensity brings notable improvement over SIR. The second model is a modified version of a stochastic shallow water model (Würsch and Craig 2013), which contains more realistic dynamical characteristics of convective scale phenomena. Using the efficient particle filter and different combination of observations of the three field variables (wind, water 'height' and rain) allows the particle filter to be evaluated in comparison to a regime where only nudging is used. Sensitivity to the properties of the model error covariance is also considered. Finally, criteria are identified under which the efficient particle filter outperforms nudging alone. References: Craig, G. C. and M. Würsch, 2012: The impact of localization and observation averaging for convective-scale data assimilation in a simple stochastic model. Q. J. R. Meteorol. Soc.,139, 515-523. Van Leeuwen, P. J., 2011: Efficient non-linear data assimilation in geophysical

  8. Estimation of complex permittivity using loop antenna

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2004-01-01

    A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna.......A method for estimating the complex permittivity of materials in the vicinity of a loop antenna is proposed. The method is based on comparing measured and numerically calculated input admittances for the loop antenna....

  9. A True Open-Loop Synchronization Technique

    DEFF Research Database (Denmark)

    Golestan, Saeed; Vidal, Ana; Yepes, Alejandro G.

    2016-01-01

    Synchronization techniques can be broadly classified into two major categories: Closed-loop and open-loop methods. The open-loop synchronization (OLS) techniques, contrary to the closed-loop ones, are unconditionally stable and benefit from a fast dynamic response. Their performance, however, tends...... is to develop a true OLS (and therefore, unconditionally stable) technique without any need for the calculation of sine and cosine functions. The effectiveness of the proposed synchronization technique is confirmed through the simulation and experimental results....

  10. Novel Natural Convection Heat Sink Design Concepts From First Principles

    Science.gov (United States)

    2016-06-01

    CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES by Derek E. Fletcher June 2016 Thesis Advisor: Garth Hobson Second Reader...COVERED Master’s Thesis 4. TITLE AND SUBTITLE NOVEL NATURAL CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES 5. FUNDING NUMBERS 6...CONVECTION HEAT SINK DESIGN CONCEPTS FROM FIRST PRINCIPLES Derek E. Fletcher Lieutenant Commander, United States Navy B.S., Southwestern

  11. International symposium on transient convective heat transfer: book of abstracts

    International Nuclear Information System (INIS)

    1996-01-01

    The international symposium on convective heat transfer was held on 19-23 August 1996, in Cesme, Izmir, Turkey. The spesialists discussed forced convection, heat exchangers, free convection and multiphase media and phase change at the meeting. Almost 53 papers were presented in the meeting

  12. 24 CFR 982.352 - Eligible housing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Eligible housing. 982.352 Section 982.352 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT...

  13. 24 CFR 81.22 - Housing plans.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Housing plans. 81.22 Section 81.22 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development THE... LOAN MORTGAGE CORPORATION (FREDDIE MAC) Housing Goals § 81.22 Housing plans. (a) If the Secretary...

  14. 24 CFR 1007.20 - Eligible housing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Eligible housing. 1007.20 Section 1007.20 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT...

  15. 20 CFR 654.407 - Housing.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Housing. 654.407 Section 654.407 Employees... EMPLOYMENT SERVICE SYSTEM Housing for Agricultural Workers Housing Standards § 654.407 Housing. (a) Housing... occupants against the elements. (b) Housing shall have flooring constructed of rigid materials, smooth...

  16. 12 CFR 1282.22 - Housing plans.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Housing plans. 1282.22 Section 1282.22 Banks and Banking FEDERAL HOUSING FINANCE AGENCY HOUSING GOALS AND MISSION ENTERPRISE HOUSING GOALS AND MISSION Housing Goals § 1282.22 Housing plans. (a) If the Director determines, under § 1282.21, that an...

  17. 24 CFR 982.619 - Cooperative housing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Cooperative housing. 982.619 Section 982.619 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN...

  18. 24 CFR 983.52 - Housing type.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Housing type. 983.52 Section 983.52 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT PROJECT-BASED...

  19. Basal melting driven by turbulent thermal convection

    Science.gov (United States)

    Rabbanipour Esfahani, Babak; Hirata, Silvia C.; Berti, Stefano; Calzavarini, Enrico

    2018-05-01

    Melting and, conversely, solidification processes in the presence of convection are key to many geophysical problems. An essential question related to these phenomena concerns the estimation of the (time-evolving) melting rate, which is tightly connected to the turbulent convective dynamics in the bulk of the melt fluid and the heat transfer at the liquid-solid interface. In this work, we consider a convective-melting model, constructed as a generalization of the Rayleigh-Bénard system, accounting for the basal melting of a solid. As the change of phase proceeds, a fluid layer grows at the heated bottom of the system and eventually reaches a turbulent convection state. By means of extensive lattice-Boltzmann numerical simulations employing an enthalpy formulation of the governing equations, we explore the model dynamics in two- and three-dimensional configurations. The focus of the analysis is on the scaling of global quantities like the heat flux and the kinetic energy with the Rayleigh number, as well as on the interface morphology and the effects of space dimensionality. Independently of dimensionality, we find that the convective-melting system behavior shares strong resemblances with that of the Rayleigh-Bénard one, and that the heat flux is only weakly enhanced with respect to that case. Such similarities are understood, at least to some extent, considering the resulting slow motion of the melting front (with respect to the turbulent fluid velocity fluctuations) and its generally little roughness (compared to the height of the fluid layer). Varying the Stefan number, accounting for the thermodynamical properties of the material, also seems to have only a mild effect, which implies the possibility of extrapolating results in numerically delicate low-Stefan setups from more convenient high-Stefan ones. Finally, we discuss the implications of our findings for the geophysically relevant problem of modeling Arctic ice melt ponds.

  20. Convective mass transfer around a dissolving bubble

    Science.gov (United States)

    Duplat, Jerome; Grandemange, Mathieu; Poulain, Cedric

    2017-11-01

    Heat or mass transfer around an evaporating drop or condensing vapor bubble is a complex issue due to the interplay between the substrate properties, diffusion- and convection-driven mass transfer, and Marangoni effects, to mention but a few. In order to disentangle these mechanisms, we focus here mainly on the convective mass transfer contribution in an isothermal mass transfer problem. For this, we study the case of a millimetric carbon dioxide bubble which is suspended under a substrate and dissolved into pure liquid water. The high solubility of CO2 in water makes the liquid denser and promotes a buoyant-driven flow at a high (solutal) Rayleigh number (Ra˜104 ). The alteration of p H allows the concentration field in the liquid to be imaged by laser fluorescence enabling us to measure both the global mass flux (bubble volume, contact angle) and local mass flux around the bubble along time. After a short period of mass diffusion, where the boundary layer thickens like the square root of time, convection starts and the CO2 is carried by a plume falling at constant velocity. The boundary layer thickness then reaches a plateau which depends on the bubble cross section. Meanwhile the plume velocity scales like (dV /d t )1 /2 with V being the volume of the bubble. As for the rate of volume loss, we recover a constant mass flux in the diffusion-driven regime followed by a decrease in the volume V like V2 /3 after convection has started. We present a model which agrees well with the bubble dynamics and discuss our results in the context of droplet evaporation, as well as high Rayleigh convection.

  1. Automation of loop amplitudes in numerical approach

    International Nuclear Information System (INIS)

    Fujimoto, J.; Ishikawa, T.; Shimizu, Y.; Kato, K.; Nakazawa, N.; Kaneko, T.

    1997-01-01

    An automatic calculating system GRACE-L1 of one-loop Feynman amplitude is reviewed. This system can be applied to 2 to 2-body one-loop processes. A sample calculation of 2 to 3-body one-loop amplitudes is also presented. (orig.)

  2. Fluctuation current in superconducting loops

    International Nuclear Information System (INIS)

    Berger, Jorge

    2012-01-01

    A superconducting loop that encloses noninteger flux holds a permanent current. On the average, this current is also present above T c , and has been measured in recent years. We are able to evaluate the permanent current within the TDGL or the Kramer-Watts-Tobin models for loops of general configuration, i.e., we don't require uniform cross section, material or temperature. We can also consider situations in which the width is not negligible in comparison to the radius. Our results agree with experiments. The situations with which we deal at present include fluctuation superconductivity in two-band superconductors, equilibrium thermal fluctuations of supercurrent along a weak link, and ratchet effects.

  3. Loop connectors in dentogenic diastema

    Directory of Open Access Journals (Sweden)

    Sanjna Nayar

    2015-01-01

    Full Text Available Patients with a missing tooth along with diastema have limited treatment options to restore the edentulous space. The use of a conventional fixed partial denture (FPD to replace the missing tooth may result in too wide anterior teeth leading to poor esthetics. Loss of anterior teeth with existing diastema may result in excess space available for pontic. This condition presents great esthetic challenge for prosthodontist. If implant supported prosthesis is not possible because of inadequate bone support, FPD along with loop connector may be a treatment option to maintain the diastema and provide optimal esthetic restoration. Here, we report a clinical case where FPD along with loop connector was used to achieve esthetic rehabilitation in maxillary anterior region in which midline diastema has been maintained.

  4. In pile helium loop ''COMEDIE''

    International Nuclear Information System (INIS)

    Abassin, J.J.; Blanchard, R.J.; Gentil, J.

    1981-01-01

    The SR1 test in the COMEDIE loop has permitted to demonstrate particularly the device operation reliability with a fuel loading. The post-irradiation examinations have pointed out the good filter efficiency and have enabled to determine the deposition profiles either for the activation products (e.g.: 51 Cr, 60 Co) or for the fission products (e.g.: sup(110m)Ag, 131 I, 134 Cs, 137 Cs). (author)

  5. Some results from the demonstration of indoor radon reduction measures in block basement houses

    International Nuclear Information System (INIS)

    Henschel, D.B.; Scott, A.G.

    1989-01-01

    Active soil ventilation techniques have been tested in 26 block-wall basement houses in eastern Pennsylvania with significantly elevated indoor radon concentrations, generally above 740 Bq/m 3 , and the results indicate that radon levels can be reduced substantially often below the U.S. Environmental Protection Agency (EPA) guideline of 148 Bq/m 3 , if effective suction can be drawn on the soil underneath the concrete slabs of these houses. Such effective suction appears achievable when either: (1) the house has a complete loop of drain tile around its footings for water drainage purposes, and suction is drawn on that loop; or (2) a sufficient number of suction pipes can be inserted at the proper locations into the crushed rock or the soil underneath the slab

  6. Dispersion relations in loop calculations

    International Nuclear Information System (INIS)

    Kniehl, B.A.

    1996-01-01

    These lecture notes give a pedagogical introduction to the use of dispersion relations in loop calculations. We first derive dispersion relations which allow us to recover the real part of a physical amplitude from the knowledge of its absorptive part along the branch cut. In perturbative calculations, the latter may be constructed by means of Cutkosky's rule, which is briefly discussed. For illustration, we apply this procedure at one loop to the photon vacuum-polarization function induced by leptons as well as to the γf anti-f vertex form factor generated by the exchange of a massive vector boson between the two fermion legs. We also show how the hadronic contribution to the photon vacuum polarization may be extracted from the total cross section of hadron production in e + e - annihilation measured as a function of energy. Finally, we outline the application of dispersive techniques at the two-loop level, considering as an example the bosonic decay width of a high-mass Higgs boson. (author)

  7. A continuous and prognostic convection scheme based on buoyancy, PCMT

    Science.gov (United States)

    Guérémy, Jean-François; Piriou, Jean-Marcel

    2016-04-01

    A new and consistent convection scheme (PCMT: Prognostic Condensates Microphysics and Transport), providing a continuous and prognostic treatment of this atmospheric process, is described. The main concept ensuring the consistency of the whole system is the buoyancy, key element of any vertical motion. The buoyancy constitutes the forcing term of the convective vertical velocity, which is then used to define the triggering condition, the mass flux, and the rates of entrainment-detrainment. The buoyancy is also used in its vertically integrated form (CAPE) to determine the closure condition. The continuous treatment of convection, from dry thermals to deep precipitating convection, is achieved with the help of a continuous formulation of the entrainment-detrainment rates (depending on the convective vertical velocity) and of the CAPE relaxation time (depending on the convective over-turning time). The convective tendencies are directly expressed in terms of condensation and transport. Finally, the convective vertical velocity and condensates are fully prognostic, the latter being treated using the same microphysics scheme as for the resolved condensates but considering the convective environment. A Single Column Model (SCM) validation of this scheme is shown, allowing detailed comparisons with observed and explicitly simulated data. Four cases covering the convective spectrum are considered: over ocean, sensitivity to environmental moisture (S. Derbyshire) non precipitating shallow convection to deep precipitating convection, trade wind shallow convection (BOMEX) and strato-cumulus (FIRE), together with an entire continental diurnal cycle of convection (ARM). The emphasis is put on the characteristics of the scheme which enable a continuous treatment of convection. Then, a 3D LAM validation is presented considering an AMMA case with both observations and a CRM simulation using the same initial and lateral conditions as for the parameterized one. Finally, global

  8. Experimental studies on natural circulation in molten salt loops

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Borgohain, A.; Maheshwari, N.K.; Vijayan, P.K.

    2015-01-01

    Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in Molten Salt Reactors (MSR’s). Two different test facilities named Molten Salt Natural Circulation Loop (MSNCL) and Molten Active Fluoride salt Loop (MAFL) have been setup for thermal hydraulics, instrument development and material related studies relevant to MSR and solar power plants. The working medium for MSNCL is a molten nitrate salt which is a mixture of NaNO 3 and KNO 3 in 60:40 ratio and proposed as one of the coolant option for molten salt based reactor and coolant as well as storage medium for solar thermal power application. On the other hand, the working medium for MAFL is a eutectic mixture of LiF and ThF 4 and proposed as a blanket salt for Indian Molten Salt Breeder Reactor (MSBR). Steady state natural circulation experiments at different power level have been performed in the MSNCL. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out in the same. A 1D code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. Further, LeBENC has been used for Pretest analysis of MAFL. This paper deals with the description of both the loops and experimental studies carried out in MSNCL. Validation of LeBENC along with the pretest analysis of MAFL using the same are also reported in this paper. (author)

  9. Strategies for Living in Houses

    Directory of Open Access Journals (Sweden)

    Colin Ripley

    2017-12-01

    Full Text Available The problem of queer housing can never go away because it is a central component of queerness. Queer housing is a contradiction in terms: not even a queer architect can design a queer house. But where does this leave us, as queer people living in a straight hegemony? Where does it leave us as humans with bodies, craving shelter and safety and a place to live that is in accordance with our experience of self and of living in the world? In this article the author proposes eight architectural strategies for re-occupying the Levittown Cape Cod house from 1947 for queer bodies, minds and hearts. These strategies offer modes by which the key programmatic formal and material components of the Cape Cod House can be attacked, made invalid, or détourned for queer uses, to make of the Cape Cod House a site for our pain, our longing, our anger.

  10. Oscillation damping of chiral string loops

    International Nuclear Information System (INIS)

    Babichev, Eugeny; Dokuchaev, Vyacheslav

    2002-01-01

    Chiral cosmic string loops tend to the stationary (vorton) configuration due to energy loss into gravitational and electromagnetic radiation. We describe the asymptotic behavior of near stationary chiral loops and their fading to vortons. General limits on the gravitational and electromagnetic energy losses by near stationary chiral loops are found. For these loops we estimate the oscillation damping time. We present solvable examples of gravitational radiation energy loss by some chiral loop configurations. The analytical dependence of string energy with time is found in the case of the chiral ring with small amplitude radial oscillations

  11. Modular invariance and covariant loop calculus

    International Nuclear Information System (INIS)

    Petersen, J.L.; Roland, K.O.; Sidenius, J.R.

    1988-01-01

    The covariant loop calculus provides and efficient technique for computing explicit expressions for the density on moduli space corresponding to arbitrary (bosonic string) loop diagrams. Since modular invariance is not manifest, however, we carry out a detailed comparison with known explicit 2- and 3- loop results derived using analytic geometry (1 loop is known to be ok). We establish identity to 'high' order in some moduli and exactly in others. Agreement is found as a result of various non-trivial cancellations, in part related to number theory. We feel our results provide very strong support for the correctness of the covariant loop calculus approach. (orig.)

  12. Algorithm for counting large directed loops

    Energy Technology Data Exchange (ETDEWEB)

    Bianconi, Ginestra [Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Gulbahce, Natali [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, NM 87545 (United States)

    2008-06-06

    We derive a Belief-Propagation algorithm for counting large loops in a directed network. We evaluate the distribution of the number of small loops in a directed random network with given degree sequence. We apply the algorithm to a few characteristic directed networks of various network sizes and loop structures and compare the algorithm with exhaustive counting results when possible. The algorithm is adequate in estimating loop counts for large directed networks and can be used to compare the loop structure of directed networks and their randomized counterparts.

  13. Functional Fourier transforms and the loop equation

    International Nuclear Information System (INIS)

    Bershadskii, M.A.; Vaisburd, I.D.; Migdal, A.A.

    1986-01-01

    The Migdal-Makeenko momentum-space loop equation is investigated. This equation is derived from the ordinary loop equation by taking the Fourier transform of the Wilson functional. A perturbation theory is constructed for the new equation and it is proved that the action of the loop operator is determined by vertex functions which coincide with those of the previous equation. It is shown how the ghost loop arises in direct iterations of the momentum-space equation with respect to the coupling constant. A simple example is used to illustrate the mechanism of appearance of an integration in the interior loops in transition to observables

  14. Modular invariance and covariant loop calculus

    International Nuclear Information System (INIS)

    Petersen, J.L.; Roland, K.O.; Sidenius, J.R.

    1988-01-01

    The covariant loop calculus provides an efficient technique for computing explicit expressions for the density on moduli space corresponding to arbitrary (bosonic string) loop diagrams. Since modular invariance is not manifest, however, we carry out a detailed comparison with known explicit two- and three-loop results derived using analytic geometry (one loop is known to be okay). We establish identity to 'high' order in some moduli and exactly in others. Agreement is found as a result of various nontrivial cancellations, in part related to number theory. We feel our results provide very strong support for the correctness of the covariant loop calculus approach. (orig.)

  15. Immigration and Swiss House Prices

    OpenAIRE

    Kathrin Degen; Andreas M. Fischer

    2010-01-01

    This study examines the behavior of Swiss house prices to immigration flows for 85 districts from 2001 to 2006. The results show that the nexus between immigration and house prices holds even in an environment of low house price inflation, nationwide rent control, and modest immigration flows. An immigration inflow equal to 1% of an area's population is coincident with an increase in prices for single-family homes of about 2.7%: a result consistent with previous studies. The overall immigrati...

  16. Women Leaders in Oxford House

    OpenAIRE

    Timpo, Phyllis; Price, Temple; Salina, Doreen; Witek, Caroline; Pommer, Nicole; Jason, Leonard A.

    2014-01-01

    This qualitative study examined women assuming leadership roles in Oxford Houses, which are communal, democratically run recovery settings for substance use disorder. Semi-structured interviews were conducted with 10 women Oxford House leaders who shared their thoughts and experiences on leadership. Several themes emerged from qualitative data analysis, most notably that stepping up and accepting a leadership role in Oxford House had a positive effect on self-esteem, which is vital to women w...

  17. Malaysian Affordability Housing Policies Revisited

    Directory of Open Access Journals (Sweden)

    Samad Diwa

    2016-01-01

    Full Text Available Housing has always been a significant aspiration of family expression and distinctly priciest investment by household. It plays a momentous role in the country’s economy and so central to the societal well-being that is emplaced in the United Nation Universal declaration of Human rights. Yet in developed and developing world alike, cities struggle to provide decent housing for lower and middle income population. The provision of affordable housing is a major policy concern around the world with Malaysia being no exception; rising income hardly keep pace with price hike of housing unit and housing interventions has majorly concentrated on demand side leading to a non-responsive supply sector. Therefore, this paper highlights affordable housing issues pertaining Malaysia. It formulates Malaysian Map of affordability and conducts an evaluation of global housing schemes to better identify policy priorities for Malaysia. It’s significant to harmonize supply and demand side factors in the housing market to ensure that housing supply fits the needs of citizens based on the location, price and target group. In case of Malaysia supply oriented initiative are of urgency in short and medium run. This must be supported by long term demand side schemes in parallel. Convergence of these two factors is essential for a balanced equilibrium and obtaining affordability.

  18. Fire Sales and House Prices

    DEFF Research Database (Denmark)

    Andersen, Steffen; Meisner Nielsen, Kasper

    We exploit a natural experiment in Denmark to investigate when forced sales lead to fire sale discounts. Forced sales result from sudden deaths of house owners in an institutional environment in which beneficiaries are forced to settle the estate, and hence sell the house, within 12 months. We...... and the urgency of the sale also affect the average discount: Discounts are larger when house prices contract, in thin markets where demand is lower, and when the sale is more likely to be a fire sale because of financial or liquidity constraints. Late fire sales are more likely when the house price...... forced sales lead to fire sale discounts....

  19. Challenges for Large Housing Estates

    DEFF Research Database (Denmark)

    Vestergaard, Hedvig

    This paper examines policies and improvement programmes implemented to improve troubled housing estates during three decades. It is based on evaluations of implemented programmes conducted for the Danish ministry of housing and the National Building Fund as well as similar studies from other...... European countries. Case studies illustrate local developments and outcomes and are the base for questioning the original identification of problems and thus the chosen solutions. Perspectives for current policy initiatives in the field of troubled housing estates are discussed in a general housing market...

  20. Social Housing: wood prefabrication techniques

    Directory of Open Access Journals (Sweden)

    Tiziana Ferrante

    2012-10-01

    Full Text Available Student housing, a particular and quite significant part of social housing, and innovation in processing and production of industrial building components made of a material (wood not adequately inquired: two fields of research that have been explored for a long time allowing here to share and compare experiences gained thus far. By a selection of samples of wooden student housing in Europe we have documented the performances of this material and we have underlined, at the same time, through what happens abroad, the need of an organic national social housing plan that can meet an unsatisfied demand and boost the construction industry during this particular stage of economic crisis.

  1. UF/sub 6/ test loop for evaluation and implementation of international enrichment plant safeguards

    International Nuclear Information System (INIS)

    Cooley, J.N.; Fields, L.W.; Swindle, D.W. Jr.

    1987-01-01

    A functional test loop capable of simulating UF/sub 6/ flows, pressures, and pipe deposits characteristic of gas centrifuge enrichment plant piping has been designed and fabricated by the Enrichment Safeguards Program of Martin Marietta Energy Systems, Inc., for use by the International Atomic Energy Agency (IAEA) at its Safeguards Analytical Laboratory in Seibersdorf, Austria. The purpose of the test loop is twofold: (1) to enable the IAEA to evaluate and to calibrate enrichment safeguards measurement instrumentation to be used in limited frequency-unannounced access (LFUA) inspection strategy measurements at gas centrifuge enrichment plants and (2) to train IAEA inspectors in the use of such instrumentation. The test loop incorporates actual sections of cascade header pipes from the centrifuge enrichment plants subject to IAEA inspections. The test loop is described, applications for its use by the IAEA are detailed, and results from an initial demonstration session using the test loop are summarized. By giving the IAEA the in-house capability to evaluate LFUA inspection strategy approaches, to develop inspection procedures, to calibrate instrumentation, and to train inspectors, the UF/sub 6/ cascade header pipe test loop will contribute to the IAEA's success in implementing LFUA strategy inspections at gas centrifuge enrichment facilities subject to international safeguards inspections

  2. Hyperstaticity and loops in frictional granular packings

    Science.gov (United States)

    Tordesillas, Antoinette; Lam, Edward; Metzger, Philip T.

    2009-06-01

    The hyperstatic nature of granular packings of perfectly rigid disks is analyzed algebraically and through numerical simulation. The elementary loops of grains emerge as a fundamental element in addressing hyperstaticity. Loops consisting of an odd number of grains behave differently than those with an even number. For odd loops, the latent stresses are exterior and are characterized by the sum of frictional forces around each loop. For even loops, the latent stresses are interior and are characterized by the alternating sum of frictional forces around each loop. The statistics of these two types of loop sums are found to be Gibbsian with a "temperature" that is linear with the friction coefficient μ when μ<1.

  3. Behaviors and transitions along the path to magnetostrophic convection

    Science.gov (United States)

    Grannan, A. M.; Vogt, T.; Horn, S.; Hawkins, E. K.; Aggarwal, A.; Aurnou, J. M.

    2017-12-01

    The generation of magnetic fields in planetary and stellar interiors are believed to be controlled primarily by turbulent convection constrained by Coriolis and Lorentz forces in their electrically conducting fluid layers. Yet relatively few laboratory experiments are capable of investigating the different regimes of turbulent magnetohydrodynamic convection. In this work, we perform one laboratory experiment in a cylinder at a fixed heat flux using the liquid metal gallium in order to investigate, sequentially: Rayleigh-Bènard convection without any imposed constraints, magnetoconvection with a Lorentz constraint imposed by vertical magnetic field, rotating convection with a Coriolis constraint imposed by rotation, and finally the magnetostrophic convective regime where both Coriolis and Lorentz are imposed and equal. Using an array of internal and external temperature probes, we show that each regime along the path to magnetostrophic convection is unique. The behaviors and transitions in the dominant modes of convection as well as their fundamental frequencies and wavenumbers are investigated.

  4. Convective equilibrium and mixing-length theory for stellarator reactors

    International Nuclear Information System (INIS)

    Ho, D.D.M.; Kulsrud, R.M.

    1985-09-01

    In high β stellarator and tokamak reactors, the plasma pressure gradient in some regions of the plasma may exceed the critical pressure gradient set by ballooning instabilities. In these regions, convective cells break out to enhance the transport. As a result, the pressure gradient can rise only slightly above the critical gradient and the plasma is in another state of equilibrium - ''convective equilibrium'' - in these regions. Although the convective transport cannot be calculated precisely, it is shown that the density and temperature profiles in the convective region can still be estimated. A simple mixing-length theory, similar to that used for convection in stellar interiors, is introduced in this paper to provide a qualitative description of the convective cells and to show that the convective transport is highly efficient. A numerical example for obtaining the density and temperature profiles in a stellarator reactor is given

  5. 24 CFR 982.606 - Congregate housing: Who may reside in congregate housing.

    Science.gov (United States)

    2010-04-01

    ... Special Housing Types Congregate Housing § 982.606 Congregate housing: Who may reside in congregate housing. (a) An elderly person or a person with disabilities may reside in a congregate housing unit. (b... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Congregate housing: Who may reside...

  6. Radionuclides in house dust

    CERN Document Server

    Fry, F A; Green, N; Hammond, D J

    1985-01-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

  7. House While Woman Grows

    Directory of Open Access Journals (Sweden)

    Şengül Öymen Gür

    2013-12-01

    Full Text Available Discourses on woman/space relations boomed in the 90s. The fundamental reason was to give support to the Feminist Movement. This trend which has had feeble effect on architectural design remained controversial. The comprehensive research expounded in this article which was based on an open-ended questionnaire that targeted at determining the gender roles at home, applied to female subjects who simulated the national demographics, clearly demonstrated that the home experience of an average Turkish woman basically consists of kitchens; the female who runs the house does not really have a place for herself at home. However she does not perceive her restrained, secondary role an issue worthy of struggling to change and she grants spaces for recreation and study to the male. The well-established civil laws conducive for equality has not changed this disturbing situation and do not seem to do so in the near future.

  8. Moisture Vertical Structure, Deep Convective Organization, and Convective Transition in the Amazon

    Science.gov (United States)

    Schiro, K. A.; Neelin, J. D.

    2017-12-01

    Constraining precipitation processes in climate models with observations is crucial to accurately simulating current climate and reducing uncertainties in future projections. Results from the Green Ocean Amazon (GOAmazon) field campaign (2014-2015) provide evidence that deep convection is strongly controlled by the availability of moisture in the free troposphere over the Amazon, much like over tropical oceans. Entraining plume buoyancy calculations confirm that CWV is a good proxy for the conditional instability of the environment, yet differences in convective onset as a function of CWV exist over land and ocean, as well as seasonally and diurnally over land. This is largely due to variability in the contribution of lower tropospheric humidity to the total column moisture. Boundary layer moisture shows a strong relationship to the onset during the day, which largely disappears during nighttime. Using S-Band radar, these transition statistics are examined separately for unorganized and mesoscale-organized convection, which exhibit sharp increases in probability of occurrence with increasing moisture throughout the column, particularly in the lower free troposphere. Retrievals of vertical velocity from a radar wind profiler indicate updraft velocity and mass flux increasing with height through the lower troposphere. A deep-inflow mixing scheme motivated by this — corresponding to deep inflow of environmental air into a plume that grows with height — provides a weighting of boundary layer and free tropospheric air that yields buoyancies consistent with the observed onset of deep convection across seasons and times of day, across land and ocean sites, and for all convection types. This provides a substantial improvement relative to more traditional constant mixing assumptions, and a dramatic improvement relative to no mixing. Furthermore, it provides relationships that are as strong or stronger for mesoscale-organized convection as for unorganized convection.

  9. Pathology of mass housing projects in Iran (Mehr Housing Plan ...

    African Journals Online (AJOL)

    Mass housing in construction industry is known as projects that mass production methods are used to construct residential units in it. Mass housing is a model of construction that has high economic, technical and managerial feasibility and should optimize three areas of quality, time and cost. But it should be noted that in ...

  10. Subsidized Housing, Public Housing, and Adolescent Violence and Substance Use

    Science.gov (United States)

    Leech, Tamara G. J.

    2012-01-01

    This study examines the separate relationships of public housing residence and subsidized housing residence to adolescent health risk behavior. Data include 2,530 adolescents aged 14 to 19 who were children of the National the Longitudinal Study of Youth. The author used stratified propensity methods to compare the behaviors of each…

  11. Coupling of convection and circulation at various resolutions

    Directory of Open Access Journals (Sweden)

    Cathy Hohenegger

    2015-03-01

    Full Text Available A correct representation of the coupling between convection and circulation constitutes a prerequisite for a correct representation of precipitation at all scales. In this study, the coupling between convection and a sea breeze is investigated across three main resolutions: large-eddy resolution where convection is fully explicit, convection-permitting resolution where convection is partly explicit and coarse resolution where convection is parameterised. The considered models are the UCLA-LES, COSMO and ICON. Despite the use of prescribed surface fluxes, comparison of the simulations reveals that typical biases associated with a misrepresentation of convection at convection-permitting and coarser resolutions significantly alter the characteristics of the sea breeze. The coarse-resolution simulations integrated without convective parameterisation and the convection-permitting simulations simulate a too slow propagation of the breeze front as compared to the large-eddy simulations. From the various factors affecting the propagation, a delayed onset and intensification of cold pools primarily explains the differences. This is a direct consequence of a delayed development of convection when the grid spacing is coarsened. Scaling the time the sea breeze reaches the centre of the land patch by the time precipitation exceeds 2 mm day−1, used as a measure for significant evaporation, yields a collapse of the simulations onto a simple linear relationship although subtle differences remain due to the use of different turbulence and microphysical schemes. Turning on the convection scheme significantly disrupts the propagation of the sea breeze due to a misrepresented timing (too early triggering and magnitude (too strong precipitation evaporation in one of the tested convection schemes of the convective processes.

  12. Development of a Measure of Housing and Housing Services.

    Science.gov (United States)

    Clark, Colleen; Young, M Scott; Teague, Gregory; Rynearson-Moody, Sarah

    2016-01-01

    The Housing Program Measure (HPM) was designed to document critical elements of a range of housing program types and associated services. Qualitative methods, including literature review and open-ended interviews, were used to determine pertinent HPM domains and to develop the pool of items. The measure was pre-tested, and reliability and validity analyses were applied to revise and strengthen the measure. The resulting measure furthers homelessness research by providing a tool that can be used to define housing and housing services interventions across diverse projects and disciplines, to facilitate program management by matching housing resources to the needs of homeless individuals, and to support model development by measuring progress to goals.

  13. Natural convection in heat-generating fluids

    International Nuclear Information System (INIS)

    Bol'shov, Leonid A; Kondratenko, Petr S; Strizhov, Valerii F

    2001-01-01

    Experimental and theoretical studies of convective heat transfer from a heat-generating fluid confined to a closed volume are reviewed. Theoretical results are inferred from analytical estimates based on the relevant conservation laws and the current understanding of the convective heat-transfer processes. Four basic and one asymptotic regime of heat transfer are identified depending on the heat generation rate. Limiting heat-transfer distribution patterns are found for the lower boundary. Heat transfer in a quasi-two-dimensional geometry is analyzed. Quasi-steady-state heat transfer from a cooling-down fluid without internal heat sources is studied separately. Experimental results and theoretical predictions are compared. (reviews of topical problems)

  14. Topology optimisation of natural convection problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Aage, Niels; Andreasen, Casper Schousboe

    2014-01-01

    This paper demonstrates the application of the density-based topology optimisation approach for the design of heat sinks and micropumps based on natural convection effects. The problems are modelled under the assumptions of steady-state laminar flow using the incompressible Navier-Stokes equations...... coupled to the convection-diffusion equation through the Boussinesq approximation. In order to facilitate topology optimisation, the Brinkman approach is taken to penalise velocities inside the solid domain and the effective thermal conductivity is interpolated in order to accommodate differences...... in thermal conductivity of the solid and fluid phases. The governing equations are discretised using stabilised finite elements and topology optimisation is performed for two different problems using discrete adjoint sensitivity analysis. The study shows that topology optimisation is a viable approach...

  15. Convective instabilities in SN 1987A

    Science.gov (United States)

    Benz, Willy; Thielemann, Friedrich-Karl

    1990-01-01

    Following Bandiera (1984), it is shown that the relevant criterion to determine the stability of a blast wave, propagating through the layers of a massive star in a supernova explosion, is the Schwarzschild (or Ledoux) criterion rather than the Rayleigh-Taylor criterion. Both criteria coincide only in the incompressible limit. Results of a linear stability analysis are presented for a one-dimensional (spherical) explosion in a realistic model for the progenitor of SN 1987A. When applying the Schwarzschild criterion, unstable regions get extended considerably. Convection is found to develop behind the shock, with a characteristic growth rate corresponding to a time scale much smaller than the shock traversal time. This ensures that efficient mixing will take place. Since the entire ejected mass is found to be convectively unstable, Ni can be transported outward, even into the hydrogen envelope, while hydrogen can be mixed deep into the helium core.

  16. Natural convection heat transfer in SIGMA experiment

    International Nuclear Information System (INIS)

    Lee, Seung Dong; Lee, Gang Hee; Suh, Kune Yull

    2004-01-01

    A loss-of-coolant accident (LOCA) results in core melt formation and relocation at various locations within the reactor core over a considerable period of time. If there is no effective cooling mechanism, the core debris may heat up and commence natural circulation. The high temperature pool of molten core material will threaten the structural integrity of the reactor vessel. The extent and urgency of this threat depend primarily upon the intensity of the internal heat sources and upon the consequent distribution of the heat fluxes on the vessel walls in contact with the molten core material pools. In such a steady molten pool convection state, the thermal loads against the vessel would be determined by the in-vessel heat transfer distribution involving convective and conductive heat transfer from the decay-heated core material pool to the lower head wall in contact with the core material. In this study, upward and downward heat transfer fraction ratio is focused on

  17. An experimental study of mixed convection

    International Nuclear Information System (INIS)

    Saez, Manuel

    1998-01-01

    The aim of our study is to establish a reliable data base for improving thermal-hydraulic codes, in the field of turbulent flows with buoyancy forces. The flow considered is mixed convection in the Reynolds and Richardson number range: Re=10"3 to 6*10"4 and Ri=10"-"4 to 1. Experiments are carried out in an upward turbulent flow between vertical parallel plates at different wall temperatures. Part 1 gives a detailed data base of turbulent mixed flow of free and forced convection. Part II presents the installation and the calibration system intended for probes calibration. Part III describes the measurement technique (constant-temperature probe and cold-wire probe) and the method for measuring the position of the hot-wire anemometer from the wall surface. The measurement accuracy is within 0.001 mm in the present system. Part IV relates the development of a method for near wall measurements. This correction procedure for hot-wire anemometer close to wall has been derived on the basis of a two-dimensional numerical study. The method permits to obtain a quantitative correction of the wall influence on hot-wires and takes into account the velocity profile and the effects the wall material has on the heat loss. Part V presents the experimental data obtained in the channel in forced and mixed convection. Results obtained in the forced convection regime serve as a verification of the measurement technique close to the wall and give the conditions at the entrance of the test section. The effects of the buoyancy force on the mean velocity and temperature profiles are confirmed. The buoyancy strongly affects the flow structure and deforms the distribution of mean velocity. The velocity profiles are asymmetric. The second section of part V gives an approach of analytical wall functions with buoyancy forces, on the basis of the experimental data obtained in the test section. (author) [fr

  18. Convection and crystal settling in sills

    Science.gov (United States)

    Gibb, Fergus G. F.; Henderson, C. Michael B.

    1992-02-01

    It has been advocated that convective and crystal settling processes play significant, and perhaps crucial, roles in magmatic differentiation. The fluid dynamics of magma chambers have been extensively studied in recent years, both theoretically and experimentally, but there is disagreement over the nature and scale of the convection, over its bearing on fractionation and possibly over whether it occurs at all. The differential distribution of modal olivine with height in differentiated alkaline basic sills provides critical evidence to resolve this controversy, at least for small to medium-large magma chambers. Our own and others' published data for such sills show that, irrespective of overall olivine content, modal olivine contents tend to increase in a roughly symmetrical manner inwards from the upper and lower margins of the sill, i.e. the distribution patterns are more often approximately D-shaped rather than the classic S-shape generally ascribed to gravity settling. We concur with the majority of other authors that this is an original feature of the filling process which has survived more or less unchanged since emplacement. We therefore conclude that the magmas have not undergone turbulent convection and that gravity settling has usually played only a minor modifying role since the intrusion of these sills. We offer a possible explanation for the apparent contradiction between fluid dynamical theory and the petrological evidence by suggesting that such sills rarely fill by the rapid injection of a single pulse of magma. Rather, they form from a series of pulses or a continuous pulsed influx over a protracted interval during which marginal cooling severely limits the potential for thermal convection.

  19. Nonlinear Convective Models of RR Lyrae Stars

    Science.gov (United States)

    Feuchtinger, M.; Dorfi, E. A.

    The nonlinear behavior of RR Lyrae pulsations is investigated using a state-of-the-art numerical technique solving the full time-dependent system of radiation hydrodynamics. Grey radiative transfer is included by a variable Eddington-factor method and we use the time-dependent turbulent convection model according to Kuhfuss (1986, A&A 160, 116) in the version of Wuchterl (1995, Comp. Phys. Comm. 89, 19). OPAL opacities extended by the Alexander molecule opacities at temperatures below 6000 K and an equation of state according to Wuchterl (1990, A&A 238, 83) close the system. The resulting nonlinear system is discretized on an adaptive mesh developed by Dorfi & Drury (1987, J. Comp. Phys. 69, 175), which is important to provide the necessary spatial resolution in critical regions like ionization zones and shock waves. Additionally, we employ a second order advection scheme, a time centered temporal discretizaton and an artificial tensor viscosity in order to treat discontinuities. We compute fundamental as well first overtone models of RR Lyrae stars for a grid of stellar parameters both with and without convective energy transport in order to give a detailed picture of the pulsation-convection interaction. In order to investigate the influence of the different features of the convection model calculations with and without overshooting, turbulent pressure and turbulent viscosity are performed and compared with each other. A standard Fourier decomposition is used to confront the resulting light and radial velocity variations with recent observations and we show that the well known RR Lyrae phase discrepancy problem (Simon 1985, ApJ 299, 723) can be resolved with these stellar pulsation computations.

  20. Natural convective heat transfer from square cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Novomestský, Marcel, E-mail: marcel.novomestsky@fstroj.uniza.sk; Smatanová, Helena, E-mail: helena.smatanova@fstroj.uniza.sk; Kapjor, Andrej, E-mail: andrej.kapjor@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 1, 010 26 Žilina (Slovakia)

    2016-06-30

    This article is concerned with natural convective heat transfer from square cylinder mounted on a plane adiabatic base, the cylinders having an exposed cylinder surface according to different horizontal angle. The cylinder receives heat from a radiating heater which results in a buoyant flow. There are many industrial applications, including refrigeration, ventilation and the cooling of electrical components, for which the present study may be applicable.

  1. Study of mixed convection in sodium pool

    International Nuclear Information System (INIS)

    Wang Zhou; Chen Yan

    1995-01-01

    The mixed convection phenomena in the sodium pool of fast reactor have been studied systematically by the two dimensional modeling method. A generalized concept of circumferential line in the cylindrical coordinates was proposed to overcome the three dimensional effect induced by the pool geometry in an analysis of two dimensional modeling. A method of sub-step in time was developed for solving the turbulent equations. The treatments on the boundary condition for the auxiliary velocity field have been proposed, and the explanation of allowing the flow function method to be used in the flow field in presence of a mass source term was given. As examples of verification, the experiments were conducted with water flow in a rectangular cavity. The results from theoretical analysis were applied to the numerical computation for the mixed convection in the cavity. The mechanism of stratified flow in the cavity was studied. A numerical calculation was carried out for the mixed convection in hot plenum of a typical fast reactor

  2. Heat transport in bubbling turbulent convection.

    Science.gov (United States)

    Lakkaraju, Rajaram; Stevens, Richard J A M; Oresta, Paolo; Verzicco, Roberto; Lohse, Detlef; Prosperetti, Andrea

    2013-06-04

    Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to numerous mechanisms, many of which are not understood in quantitative detail. An important component of the overall process is that the buoyancy of the bubble compounds with that of the liquid to give rise to a much-enhanced natural convection. In this article, we focus specifically on this enhancement and present a numerical study of the resulting two-phase Rayleigh-Bénard convection process in a cylindrical cell with a diameter equal to its height. We make no attempt to model other aspects of the boiling process such as bubble nucleation and detachment. The cell base and top are held at temperatures above and below the boiling point of the liquid, respectively. By keeping this difference constant, we study the effect of the liquid superheat in a Rayleigh number range that, in the absence of boiling, would be between 2 × 10(6) and 5 × 10(9). We find a considerable enhancement of the heat transfer and study its dependence on the number of bubbles, the degree of superheat of the hot cell bottom, and the Rayleigh number. The increased buoyancy provided by the bubbles leads to more energetic hot plumes detaching from the cell bottom, and the strength of the circulation in the cell is significantly increased. Our results are in general agreement with recent experiments on boiling Rayleigh-Bénard convection.

  3. Modeling mantle convection in the spherical annulus

    Science.gov (United States)

    Hernlund, John W.; Tackley, Paul J.

    2008-12-01

    Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.

  4. Loop diagrams without γ matrices

    International Nuclear Information System (INIS)

    McKeon, D.G.C.; Rebhan, A.

    1993-01-01

    By using a quantum-mechanical path integral to compute matrix elements of the form left-angle x|exp(-iHt)|y right-angle, radiative corrections in quantum-field theory can be evaluated without encountering loop-momentum integrals. In this paper we demonstrate how Dirac γ matrices that occur in the proper-time ''Hamiltonian'' H lead to the introduction of a quantum-mechanical path integral corresponding to a superparticle analogous to one proposed recently by Fradkin and Gitman. Direct evaluation of this path integral circumvents many of the usual algebraic manipulations of γ matrices in the computation of quantum-field-theoretical Green's functions involving fermions

  5. Perturbation calculations with Wilson loop

    International Nuclear Information System (INIS)

    Peixoto Junior, L.B.

    1984-01-01

    We present perturbative calculations with the Wilson loop (WL). The dimensional regularization method is used with a special attention concerning to the problem of divergences in the WL expansion in second and fourth orders, in three and four dimensions. We show that the residue in the pole, in 4d, of the fourth order graphs contribution sum is important for the charge renormalization. We compute up to second order the exact expression of the WL, in three-dimensional gauge theories with topological mass as well as its assimptotic behaviour for small and large distances. the author [pt

  6. Natural convection of nanofluids over a convectively heated vertical plate embedded in a porous medium

    Energy Technology Data Exchange (ETDEWEB)

    Ghalambaz, M.; Noghrehabadi, A.; Ghanbarzadeh, A., E-mail: m.ghalambaz@gmail.com, E-mail: ghanbarzadeh.a@scu.ac.ir [Department of Mechanical Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of)

    2014-04-15

    In this paper, the natural convective flow of nanofluids over a convectively heated vertical plate in a saturated Darcy porous medium is studied numerically. The governing equations are transformed into a set of ordinary differential equations by using appropriate similarity variables, and they are numerically solved using the fourth-order Runge-Kutta method associated with the Gauss-Newton method. The effects of parametric variation of the Brownian motion parameter (Nb), thermophoresis parameter (Nt) and the convective heating parameter (Nc) on the boundary layer profiles are investigated. Furthermore, the variation of the reduced Nusselt number and reduced Sherwood number, as important parameters of heat and mass transfer, as a function of the Brownian motion, thermophoresis and convective heating parameters is discussed in detail. The results show that the thickness of the concentration profiles is much lower than the temperature and velocity profiles. For low values of the convective heating parameter (Nc), as the Brownian motion parameter increases, the non-dimensional wall temperature increases. However, for high values of Nc, the effect of the Brownian motion parameter on the non-dimensional wall temperature is not significant. As the Brownian motion parameter increases, the reduced Sherwood number increases and the reduced Nusselt number decreases. (author)

  7. Gauge theory loop operators and Liouville theory

    International Nuclear Information System (INIS)

    Drukker, Nadav; Teschner, Joerg

    2009-10-01

    We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S 4 - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)

  8. Gauge theory loop operators and Liouville theory

    Energy Technology Data Exchange (ETDEWEB)

    Drukker, Nadav [Humboldt Univ. Berlin (Germany). Inst. fuer Physik; Gomis, Jaume; Okuda, Takuda [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Teschner, Joerg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-10-15

    We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S{sup 4} - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)

  9. Counting the cost of housing

    NARCIS (Netherlands)

    Michiel Ras; Evelien Eggink; Edwin van Gameren; Ingrid Ooms

    2006-01-01

    Original title: Uitgerekend wonen. The Dutch government exerts a great influence on the housing costs incurred by households. Tenants can apply for housing subsidy, while owner-occupiers can set their mortgage interest against their income tax. These measures have existed for a long time, but

  10. Studies on Dutch Housing Corporations

    NARCIS (Netherlands)

    Veenstra, Jacob

    2016-01-01

    One third of all dwellings in the Netherlands is owned by housing corporations. These are privately governed institutions executing a public task (social housing). Recently, corporations have received negative attention due to various incidents (such as fraud and excessive risk-taking). This put

  11. Smart Houses and Uncomfortable Homes.

    Science.gov (United States)

    Alm, Norman; Arnott, John

    2015-01-01

    In order for smart houses to achieve acceptance from potential beneficiaries they will need to match the users' expectation that their house is also their home, with the sense of privacy and control that this implies. Designers of this technology will need to be aware of findings in this regard from fields such as architecture and design ethnography.

  12. Quality assurance for passive houses

    NARCIS (Netherlands)

    Visscher, H.J.; Mlecnik, E.

    2009-01-01

    For newly built houses national ambitions prescribe increasing levels of energy performances, even including achieving net zero energy or carbon neutral houses. This is in large contrast with the lack of quality in many building processes. The building regulations, processes and control will have to

  13. The Philosophy of University Housing

    Science.gov (United States)

    Wallace, James A.

    2012-01-01

    This article examines a stated philosophy of university housing and the philosophy's effect on the facilitation of the personal and intellectual growth of students residing in the residence halls and the development of a sense of community. This particular philosophy governs the housing operations at Southern Illinois University at Carbondale.…

  14. Renewal of Postwar Housing Architecture

    DEFF Research Database (Denmark)

    Bech-Danielsen, Claus

    2015-01-01

    This paper assesses Danish postwar housing architecture in relation to the concept of ‘everyday tectonics’. It is argued that the extensive criticism of the architecture of the postwar housing developments is probably linked to their tectonic qualities, but that, to an even higher degree...

  15. Support housing for radioisotope generation

    International Nuclear Information System (INIS)

    Fries, B.A.

    1976-01-01

    A support housing for on-site radioisotope generation is disclosed in which the formation of a short-lived daughter radioisotope from its longer-lived parent features countercurrent batch flow of the eluting reagent interior of the housing. 6 claims, 4 drawing figures

  16. SYNTHESIS OF INFORMATION SYSTEM FOR SMART HOUSE HARDWARE MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Vikentyeva Olga Leonidovna

    2017-10-01

    Full Text Available Subject: smart house maintenance requires taking into account a number of factors: resource-saving, reduction of operational expenditures, safety enhancement, providing comfortable working and leisure conditions. Automation of the corresponding engineering systems of illumination, climate control, security as well as communication systems and networks via utilization of contemporary technologies (e.g., IoT - Internet of Things poses a significant challenge related to storage and processing of the overwhelmingly massive volume of data whose utilization extent is extremely low nowadays. Since a building’s lifespan is large enough and exceeds the lifespan of codes and standards that take into account the requirements of safety, comfort, energy saving, etc., it is necessary to consider management aspects in the context of rational use of large data at the stage of information modeling. Research objectives: increase the efficiency of managing the subsystems of smart buildings hardware on the basis of a web-based information system that has a flexible multi-level architecture with several control loops and an adaptation model. Materials and methods: since a smart house belongs to man-machine systems, the cybernetic approach is considered as the basic method for design and research of information management system. Instrumental research methods are represented by set-theoretical modelling, automata theory and architectural principles of organization of information management systems. Results: a flexible architecture of information system for management of smart house hardware subsystems has been synthesized. This architecture encompasses several levels: client level, application level and data level as well as three layers: presentation level, actuating device layer and analytics layer. The problem of growing volumes of information processed by realtime message controller is attended by employment of sensors and actuating mechanisms with configurable

  17. Integrated decision-making about housing, energy and wellbeing: a qualitative system dynamics model.

    Science.gov (United States)

    Macmillan, Alexandra; Davies, Michael; Shrubsole, Clive; Luxford, Naomi; May, Neil; Chiu, Lai Fong; Trutnevyte, Evelina; Bobrova, Yekatherina; Chalabi, Zaid

    2016-03-08

    The UK government has an ambitious goal to reduce carbon emissions from the housing stock through energy efficiency improvements. This single policy goal is a strong driver for change in the housing system, but comes with positive and negative "unintended consequences" across a broad range of outcomes for health, equity and environmental sustainability. The resulting policies are also already experiencing under-performance through a failure to consider housing as a complex system. This research aimed to move from considering disparate objectives of housing policies in isolation to mapping the links between environmental, economic, social and health outcomes as a complex system. We aimed to support a broad range of housing policy stakeholders to improve their understanding of housing as a complex system through a collaborative learning process. We used participatory system dynamics modelling to develop a qualitative causal theory linking housing, energy and wellbeing. Qualitative interviews were followed by two interactive workshops to develop the model, involving representatives from national and local government, housing industries, non-government organisations, communities and academia. More than 50 stakeholders from 37 organisations participated. The process resulted in a shared understanding of wellbeing as it relates to housing; an agreed set of criteria against which to assess to future policy options; and a comprehensive set of causal loop diagrams describing the housing, energy and wellbeing system. The causal loop diagrams cover seven interconnected themes: community connection and quality of neighbourhoods; energy efficiency and climate change; fuel poverty and indoor temperature; household crowding; housing affordability; land ownership, value and development patterns; and ventilation and indoor air pollution. The collaborative learning process and the model have been useful for shifting the thinking of a wide range of housing stakeholders towards a more

  18. Transport studies of radon in limestone underlying houses

    International Nuclear Information System (INIS)

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    In hilly limestone terrains of the southern Appalachians, subterranean networks of solution cavities and fissures present circulatory systems facilitating convective and advective transport of radon-bearing gas. Evidence suggests that the primary driving forces for transport are aerostatic pressure differentials created by the difference between the underground and the outside air temperatures. Examples are presented of houses experiencing elevated indoor radon levels as a consequence of communicating with such subsurface transportation systems. The location of a house near the upper or lower end of a subterranean-circulatory system seems to produce amplification of indoor radon levels in winter or summer, respectively. The transport mechanism for radon-bearing air in karst and its impact on indoor radon need better understanding, both in regard to evaluating the geographical prevalence of the phenomenon and the induced spatial and temporal effects that are possible. This paper reports field studies made at houses in karst regions at Oak Ridge, Tennessee, and Huntsville, Alabama. A primary radon-transport mechanism is advocated of ascending or descending subsurface columns of air whose flows are largely driven by aerostatic pressure gradients created by the inground-outdoor air temperature differentials. 5 refs., 5 figs., 1 tab

  19. Hourly indoor radon measurements in a research house.

    Science.gov (United States)

    Sesana, Lucia; Begnini, Stefania

    2004-01-01

    This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Prealps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of (222)Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence.

  20. Hourly indoor radon measurements in a research house

    International Nuclear Information System (INIS)

    Sesana, L.; Begnini, S.

    2004-01-01

    This paper reports and discusses the behaviour of radon concentration with time in an uninhabited dwelling. The relationship between variations in radon concentrations and indoor-outdoor temperatures and wind intensity has also been discussed. Radon concentration was measured hourly in a house located at a height of 800 m in the Lombard Pre-alps, at the top of the Valassina valley. The wind velocity and indoor-outdoor temperatures were measured by means of a meteorological station located on the terrace of the house. The data were analysed using the LBL model for indoor-outdoor air exchange and the models for the indoor accumulation of radon due to exhalation from building materials and pressure-driven infiltrations located underground. The role of wind and indoor-outdoor temperatures were analysed. The agreement of measurements with modelling clearly demonstrates the importance of the different sources of indoor radon. As the investigation was conducted in an uninhabited house, the measurements were not affected by the behaviour of people, e.g. opening and closing of windows. Measurements of the outdoor atmospheric concentrations of 222 Rn provide an index of the atmospheric stability, the formation of thermal inversions and convective turbulence. (authors)

  1. The demise of compound houses

    DEFF Research Database (Denmark)

    Andreasen, Jørgen; Eskemose Andersen, Jørgen

    2006-01-01

    of compound housing and analyses the advantages and disadvantages of life within such housing in Kumasi. Issues of privacy, image and communal life are usually cited by occupants dissatiesfied with life in compound houses, and the difficulty of extending them without spoiling the open spaces...... perceptions of what is acceptable urban life to the growing cohort of young African households. In addition, there is a need to explore innovative forms of tenure in order to secure the majority of Kumasi's population access to land for housing.......The compound house has long provided the accomodation required by low income households in West African cities. In Kumasi, Ghana, evidence suggests that no new compounds are being built. Instead, the city is being ringed by relatively affluent villa-style development while neighbourhoods dominated...

  2. Housing, energy and the environment

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    In 1985 the Association published An Energy Policy for Housing, setting out recommendations for action by local authorities and central Government to tackle the problem of fuel poverty and the improvement of the energy efficiency of the nation's housing. Based on a survey of Association members and discussions with other relevant organisations, the report then concluded that, ''the Government has yet to demonstrate any real commitment to positive investment in an energy efficient housing stock''. Five years later, the Association decided to undertake another survey to establish the extent to which its recommendations have been acted upon and to assess other factors which might have affected the achievement of any energy efficient housing stock. This report is the result of that new survey and it shows that, whilst many more authorities have made progress in developing good practice, much local authority housing is still energy inefficient and many low income households still suffer from fuel poverty. (author).

  3. Housing Welfare Policies in Scandinavia

    DEFF Research Database (Denmark)

    Jensen, Lotte

    2013-01-01

    It is commonplace to refer to the Nordic countries of Sweden, Norway, Denmark, Finland and Iceland as a distinctive and homogenous welfare regime. As far as social housing is concerned, however, the institutional heritage of the respective countries significantly frames the ways in which social...... housing is understood, regulated and subsidized, and, in turn, how housing regimes respond to the general challenges to the national welfare states. The paper presents a historical institutionalist approach to understanding the diversity of regime responses in the modern era characterized by increasing...... marketization, welfare criticism and internationalization. The aim is to provide outside readers a theoretically guided empirical insight into Scandinavian social housing policy. The paper first lines up the core of the inbuilt argument of historical institutionalism in housing policy. Secondly, it briefly...

  4. Unitary Housing Regimes in Transition

    DEFF Research Database (Denmark)

    Bengtsson, Bo; Jensen, Lotte

    2013-01-01

    Path dependence is strong in housing institutions and policy. In both Denmark and Sweden, today’s universal and ‘unitary’ (Kemeny) housing regimes can be traced back to institutions that were introduced fifty years back in history or more. Recently, universal and unitary housing systems...... in Scandinavia, and elsewhere, are under challenge from strong political and economic forces. These challenges can be summarized as economic cutbacks, privatization and Europeanization. Although both the Danish and the Swedish housing system are universal and unitary in character, they differ considerably...... in institutional detail. Both systems have corporatist features, however in Denmark public housing is based on local tenant democracy and control, and in Sweden on companies owned and controlled by the municipalities, combined with a centralized system of rent negotiations. In the paper the present challenges...

  5. The solar house that rotates

    International Nuclear Information System (INIS)

    Miloni, R.P.

    2001-01-01

    This article describes an innovative solar building in Weiz, Austria, that uses passive solar technologies, photovoltaics and a ground-coupled heat pump to cover its minimal energy requirements. The house, which follows the sun by rotating around its central axis, is described in detail, including its climatic design and its 'plus-energy' concept. Details are also given on the materials used in the house's construction and the functioning of its thermal insulation. The various operating modes of the house from the systems point of view are described for differing seasons and climatic extremes. Marketing aspects for this standardised house, featuring personal-computer-based on-line definition of facade cladding, fittings, photovoltaic power, furnishings etc. and real-time rendering of the house are also discussed

  6. Women's housing conditions in Bangladesh.

    Science.gov (United States)

    Shefali, M K

    1996-01-01

    This news article describes women's housing conditions, housing policy, and pilot programs to house poor women in Bangladesh. Although Bangladesh has a constitution that reinforces the equal status of women, in practice, men dominate and patrilineal customs determine inheritance and property rights. Religious affiliation also determines land tenure and inheritance. Muslim women can inherit 12.5% of their husband's property if there are children. 25% is inherited if wives are without children. Hindu women without sons can inherit their husband's property, but not parental property. Many families refuse to release property to women without a fight. Women, regardless of ownership of land, rarely control or use their land. The custom of requiring men to maintain wives during the marriage, and daughters until marriage, creates obstacles to women's decision making about property. Without collateral and other security women are unable to secure bank loans. Many women are also constrained by the requirement of male consent or guarantees for bank transactions. Banks do not have a gender responsive criteria for selecting loan recipients. The government does not provide sufficient housing to satisfy the growing housing needs due to population growth. Some housing is available from slum landlords. A National Housing Policy was formulated in 1993. Priority would be given to the housing needs of low income women in urban areas and women-headed households with income below the poverty line. The policy does not address the underlying factors that prevent equal access to housing for women. The government prepared a Human Settlement and Urban Development proposal for the Habitat II conference. The plan did not address gender issues. Special efforts are being made by nongovernmental groups to meet the housing needs of professional women and for some disadvantaged women.

  7. Convective Heat Transfer Coefficients of the Human Body under Forced Convection from Ceiling

    DEFF Research Database (Denmark)

    Kurazumi, Yoshihito; Rezgals, Lauris; Melikov, Arsen Krikor

    2014-01-01

    The average convective heat transfer coefficient for a seated human body exposed to downward flow from above was determined. Thermal manikin with complex body shape and size of an average Scandinavian female was used. The surface temperature distribution of the manikin’s body was as the skin...... of the convective heat transfer coefficient of the whole body (hc [W/(m2•K)]) was proposed: hc=4.088+6.592V1.715 for a seated naked body at 20ºC and hc=2.874+7.427V1.345 for a seated naked body at 26ºC. Differences in the convective heat transfer coefficient of the whole body in low air velocity range, V

  8. Housing Systems and Ethnic Spatial Segregation

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter; Andersson, Roger; Wessel, Terje

    Residential spatial segregation is related to housing markets and housing policies. In this paper, ethnic segregation is compared across four Nordic capitals and explanations for the differences are examined by comparing the housing markets and housing policies of the countries. The housing markets...

  9. The First "Comfort Houses" in Denmark

    DEFF Research Database (Denmark)

    Brunsgaard, Camilla; Knudstrup, Mary-Ann; Heiselberg, Per

    2009-01-01

    The "Comfort Houses" is the most ambitious building project in passive houses in Denmark until today. Eight single family houses are built and designed by seven different consortiums. Besides fulfilling the German passive house standard the goal was to build the houses according to Danish tradition...

  10. Creating Affordable Housing through self-management:

    DEFF Research Database (Denmark)

    Jensen, Jesper Ole; Stensgaard, Anne Gro

    The paper presents a case on self-management in the Danish social housing sector as a way of providing affordable housing. It is based on an evaluation of a Danish concept for affordable housing, Social Housing Plus (“AlmenBolig+”). The concept was introduced in 2007, and so far app 1.400 housing...

  11. 38 CFR 18.445 - Housing.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Housing. 18.445 Section....445 Housing. (a) Housing provided by a recipient. A recipient that provides housing to its nonhandicapped students shall provide comparable, convenient, and accessible housing to qualified handicapped...

  12. 24 CFR 3.405 - Housing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Housing. 3.405 Section 3.405 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 3.405 Housing. (a) Generally...

  13. 20 CFR 654.404 - Housing site.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Housing site. 654.404 Section 654.404... THE EMPLOYMENT SERVICE SYSTEM Housing for Agricultural Workers Housing Standards § 654.404 Housing site. (a) Housing sites shall be well drained and free from depressions in which water may stagnate...

  14. 7 CFR 1944.659 - Replacement housing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement housing...

  15. 34 CFR 104.45 - Housing.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Housing. 104.45 Section 104.45 Education Regulations of... Postsecondary Education § 104.45 Housing. (a) Housing provided by the recipient. A recipient that provides housing to its nonhandicapped students shall provide comparable, convenient, and accessible housing to...

  16. 45 CFR 605.45 - Housing.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Housing. 605.45 Section 605.45 Public Welfare... § 605.45 Housing. (a) Housing provided by the recipient. A recipient that provides housing to its nonhandicapped students shall provide comparable, convenient, and accessible housing to handicapped students at...

  17. HOUSING INSURANCE IN ROMANIA

    Directory of Open Access Journals (Sweden)

    FLOREA IANC MARIA MIRABELA

    2014-12-01

    Full Text Available Last few years have shown that Romania is not protected from the consequences of climate change. It is clear that type flood events may cause social problems and losses is difficult financing from public resources, especially in the context of the existence of budget constraints. The only viable system to cope with such disasters is insurance system that has the ability to spread risks by reinsurance Natural disasters - earthquakes, floods, landslides - are just some of the risks that may threaten your home. And if natural disasters can seem distant danger, think as fires, floods caused by broken pipes or theft of household goods are trouble can happen anytime to anyone. To protect yourself in such unpleasant situations, whose frequency is unfortunately on the rise, it is necessary to be assured. Thus, you will be able to recover losses in the event that they occur. The house is undoubtedly one of the most important assets we own. Therefore, the Romans began to pay increasingly more attention to domestic insurance products. Since 2011, voluntary home insurance, life insurance with, were the most dynamic segments of the market.

  18. Convergence behavior of idealized convection-resolving simulations of summertime deep moist convection over land

    Science.gov (United States)

    Panosetti, Davide; Schlemmer, Linda; Schär, Christoph

    2018-05-01

    Convection-resolving models (CRMs) can explicitly simulate deep convection and resolve interactions between convective updrafts. They are thus increasingly used in numerous weather and climate applications. However, the truncation of the continuous energy cascade at scales of O (1 km) poses a serious challenge, as in kilometer-scale simulations the size and properties of the simulated convective cells are often determined by the horizontal grid spacing (Δ x ).In this study, idealized simulations of deep moist convection over land are performed to assess the convergence behavior of a CRM at Δ x = 8, 4, 2, 1 km and 500 m. Two types of convergence estimates are investigated: bulk convergence addressing domain-averaged and integrated variables related to the water and energy budgets, and structural convergence addressing the statistics and scales of individual clouds and updrafts. Results show that bulk convergence generally begins at Δ x =4 km, while structural convergence is not yet fully achieved at the kilometer scale, despite some evidence that the resolution sensitivity of updraft velocities and convective mass fluxes decreases at finer resolution. In particular, at finer grid spacings the maximum updraft velocity generally increases, and the size of the smallest clouds is mostly determined by Δ x . A number of different experiments are conducted, and it is found that the presence of orography and environmental vertical wind shear yields more energetic structures at scales much larger than Δ x , sometimes reducing the resolution sensitivity. Overall the results lend support to the use of kilometer-scale resolutions in CRMs, despite the inability of these models to fully resolve the associated cloud field.

  19. Do housing regimes matter? : Assessing the concept of housing regimes through configurations of housing outcomes

    NARCIS (Netherlands)

    Dewilde, C.L.

    2017-01-01

    Based on a conceptualisation of de-commodification as the right to decent and affordable housing, we assessed to what extent this right is realised for low-to-moderate-income owners and renters across Western European housing regimes in 1995 and 2012. If differences in the social production of

  20. Loop quantization as a continuum limit

    International Nuclear Information System (INIS)

    Manrique, Elisa; Oeckl, Robert; Weber, Axel; Zapata, Jose A

    2006-01-01

    We present an implementation of Wilson's renormalization group and a continuum limit tailored for loop quantization. The dynamics of loop-quantized theories is constructed as a continuum limit of the dynamics of effective theories. After presenting the general formalism we show as a first explicit example the 2D Ising field theory, an interacting relativistic quantum field theory with local degrees of freedom quantized by loop quantization techniques

  1. Quantum chromodynamics as dynamics of loops

    International Nuclear Information System (INIS)

    Makeenko, Yu.M.; Migdal, A.A.

    1981-01-01

    QCD is entirely reformulated in terms of white composite fields - the traces of the loop products. The 1/N expansion turns out to be the WKB (Hartree-Fock) approximation for these fields. The 'classical' equation describing the N = infinite case is reduced tp a bootstrap form. New, manifestly gauge-invariant perturbation theory in the loop space, reproducing asymptotic freedom, is developed by iterations of this equation. The area law appears to be a self-consistent solution at large loops. (orig.)

  2. Lattice QED in the loop space

    International Nuclear Information System (INIS)

    Fort, H.

    1994-01-01

    We present a survey on the state of the art in the formulation of lattice compact QED in the space of loops. In a first part we review our most recent Hamiltonian results which signal a second order transition for (3+1) compact QED. We devote the second part to the Lagrangian loop formalism, showing the equivalence of the recently proposed loop action with the Villain form. (orig.)

  3. LMFBR with booster pump in pumping loop

    International Nuclear Information System (INIS)

    Rubinstein, H.J.

    1975-01-01

    A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation

  4. 75 FR 5706 - Federal Housing Administration: Insurance for Manufactured Housing: Reopening of Public Comment...

    Science.gov (United States)

    2010-02-04

    ... 2502-AI45 Federal Housing Administration: Insurance for Manufactured Housing: Reopening of Public.... ACTION: Proposed rule; reopening of public comment period. SUMMARY: On September 15, 2008, HUD published a proposed rule entitled ``Federal Housing Administration: Insurance for Manufactured Housing.'' The...

  5. Soft Neutrosophic Loops and Their Generalization

    Directory of Open Access Journals (Sweden)

    Mumtaz Ali

    2014-06-01

    Full Text Available Soft set theory is a general mathematical tool for dealing with uncertain, fuzzy, not clearly defined objects. In this paper we introduced soft neutrosophic loop,soft neutosophic biloop, soft neutrosophic N -loop with the discuission of some of their characteristics. We also introduced a new type of soft neutrophic loop, the so called soft strong neutrosophic loop which is of pure neutrosophic character. This notion also found in all the other corresponding notions of soft neutrosophic thoery. We also given some of their properties of this newly born soft structure related to the strong part of neutrosophic theory.

  6. Vertically Polarized Omnidirectional Printed Slot Loop Antenna

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper

    2015-01-01

    A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

  7. Quantum chromodynamics as dynamics of loops

    International Nuclear Information System (INIS)

    Makeenko, Yu.; Migdal, A.A.

    1980-01-01

    The problem of a possibility of reformulating quantum chromodynamics (QCD) in terms of colourless composite fields instead of coloured quarks and gluons is considered. The role of such fields is played by the gauge invariant loop functionals. The Shwinger equations of motion is derived in the loop space which completely describe dynamics of the loop fields. New manifestly gauge invariant diagram technique in the loop space is developed. These diagrams reproduce asymptotic freedom in the ultraviolet range and are consistent with the confinement law in the infrared range

  8. Vorticity imbalance and stability in relation to convection

    Science.gov (United States)

    Read, W. L.; Scoggins, J. R.

    1977-01-01

    A complete synoptic-scale vorticity budget was related to convection storm development in the eastern two-thirds of the United States. The 3-h sounding interval permitted a study of time changes of the vorticity budget in areas of convective storms. Results of analyses revealed significant changes in values of terms in the vorticity equation at different stages of squall line development. Average budgets for all areas of convection indicate systematic imbalance in the terms in the vorticity equation. This imbalance resulted primarily from sub-grid scale processes. Potential instability in the lower troposphere was analyzed in relation to the development of convective activity. Instability was related to areas of convection; however, instability alone was inadequate for forecast purposes. Combinations of stability and terms in the vorticity equation in the form of indices succeeded in depicting areas of convection better than any one item separately.

  9. A Thermodynamically General Theory for Convective Circulations and Vortices

    Science.gov (United States)

    Renno, N. O.

    2007-12-01

    Convective circulations and vortices are common features of atmospheres that absorb low-entropy-energy at higher temperatures than they reject high-entropy-energy to space. These circulations range from small to planetary-scale and play an important role in the vertical transport of heat, momentum, and tracer species. Thus, the development of theoretical models for convective phenomena is important to our understanding of many basic features of planetary atmospheres. A thermodynamically general theory for convective circulations and vortices is proposed. The theory includes irreversible processes and quantifies the pressure drop between the environment and any point in a convective updraft. The article's main result is that the proposed theory provides an expression for the pressure drop along streamlines or streamtubes that is a generalization of Bernoulli's equation to convective circulations. We speculate that the proposed theory not only explains the intensity, but also shed light on other basic features of convective circulations and vortices.

  10. Thermo-electro-hydrodynamic convection under microgravity: a review

    Energy Technology Data Exchange (ETDEWEB)

    Mutabazi, Innocent; Yoshikawa, Harunori N; Fogaing, Mireille Tadie; Travnikov, Vadim; Crumeyrolle, Olivier [Laboratoire Ondes et Milieux Complexes, UMR 6294, CNRS-Université du Havre, CS 80450, F-76058 Le Havre Cedex (France); Futterer, Birgit; Egbers, Christoph, E-mail: Innocent.Mutabazi@univ-lehavre.fr [Department of Aerodynamics and Fluid Mechanics, Brandenburg University of Technology Cottbus-Senftenberg, Cottbus (Germany)

    2016-12-15

    Recent studies on thermo-electro-hydrodynamic (TEHD) convection are reviewed with focus on investigations motivated by the analogy with natural convection. TEHD convection originates in the action of the dielectrophoretic force generated by an alternating electric voltage applied to a dielectric fluid with a temperature gradient. This electrohydrodynamic force is analogous to Archimedean thermal buoyancy and can be regarded as a thermal buoyancy force in electric effective gravity. The review is concerned with TEHD convection in plane, cylindrical, and spherical capacitors under microgravity conditions, where the electric gravity can induce convection without any complexities arising from geometry or the buoyancy force due to the Earth’s gravity. We will highlight the convection in spherical geometry, comparing developed theories and numerical simulations with the GEOFLOW experiments performed on board the International Space Station (ISS). (paper)

  11. In pile helium loop ''Comedie''

    International Nuclear Information System (INIS)

    Blanchard, R.J.

    1985-01-01

    The loop is located in the SILOE reactor at Centre d'Etudes Nucleaires de Grenoble. The purpose and objectives are divided into two groups, principal and secondary. The primary objective was to provide basic data on the deposition behavior of important condensable fission products on a variety of steel surfaces, i.e. temperature (sorption isotherms) and mass transfer (physical adsorption) dependencies; to provide information concerning the degree of penetration of important fission products into the metals comprising the heat exchanger-recuperator tubes as a function of alloy type and/or metal temperature; to provide complementary information on the reentrainment (liftoff) of important fission and activation products by performing out-of-pile blowdown experiments on tube samples representative of the alloy types used in the heat exchanger-recuperator and of the surface temperatures experienced during plateout. The secondary objective was to provide information concerning the migration of important fission products through graphite. To this end, concentration profiles in the web between the fuel rods containing the fission product source and the coolant channels and in the graphite diffusion sample will be measured to study the corrosion of metallic specimens placed in the conditions of high temperature gas cooled reactor. The first experiment SRO enables to determine the loop characteristics and possibilities related to thermal, thermodynamic, chemical and neutronic properties. The second experiment has been carried out in high temperature gas cooled reactor operating conditions. It enables to determine in particular the deposition axial profile of activation and fission products in the plateout section constituting the heat exchanger, the fission products balance trapped in the different filter components, and the cumulated released fraction of solid fission products. The SR1 test permits to demonstrate in particular the Comedie loop operation reliability, either

  12. Housing Choice Voucher Program Support Division (PSD)

    Data.gov (United States)

    Department of Housing and Urban Development — Housing Choice Voucher (HCV) Program Management Programmatic Report for April to June 2010. This is inofrmation collected from Housing Authorities across the nation...

  13. 75 FR 66977 - Housing Trust Fund

    Science.gov (United States)

    2010-10-29

    ...., administrative requirements; monitoring, site and neighborhood standards; and affirmative marketing). This... affordable multifamily rental housing. Income Targeting Based on tabulations of American Housing Survey data... housing for ELI households. The Secretary shall publish subsequent income targeting requirements when HUD...

  14. CoC Housing Inventory Count Reports

    Data.gov (United States)

    Department of Housing and Urban Development — Continuum of Care (CoC) Homeless Assistance Programs Housing Inventory Count Reports are a snapshot of a CoC’s housing inventory, available at the national and state...

  15. Rapid Simulation of Flat Knitting Loops Based On the Yarn Texture and Loop Geometrical Model

    Directory of Open Access Journals (Sweden)

    Lu Zhiwen

    2017-06-01

    Full Text Available In order to create realistic loop primitives suitable for the fast computer-aided design (CAD of the flat knitted fabric, we have a research on the geometric model of the loop as well as the variation of the loop surface. Establish the texture variation model based on the changing process from the normal yarn to loop that provides the realistic texture of the simulative loop. Then optimize the simulative loop based on illumination variation. This paper develops the computer program with the optimization algorithm and achieves the loop simulation of different yarns to verify the feasibility of the proposed algorithm. Our work provides a fast CAD of the flat knitted fabric with loop simulation, and it is not only more realistic but also material adjustable. Meanwhile it also provides theoretical value for the flat knitted fabric computer simulation.

  16. House price responsiveness of housing investments across major European economies

    OpenAIRE

    Gattini, Luca; Ganoulis, Ioannis

    2012-01-01

    In comparison with the large literature on house prices, housing investments have been studied far less. This paper investigates the behaviour of private residential investments for the six largest European economies, namely: Germany, France, Italy, Spain, the Netherlands and the United Kingdom. It employs a common modelling structure based on an error correction approach and country specific models. First, co-integration among the parsimoniously specified set of fundamental variables is dete...

  17. Primary Issues of Mixed Convection Heat Transfer Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Myeong-Seon; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    The computer code analyzing the system operating and transient behavior must distinguish flow conditions involved with convective heat transfer flow regimes. And the proper correlations must be supplied to those flow regimes. However the existing safety analysis codes are focused on the Light Water Reactor and they are skeptical to be applied to the GCRs (Gas Cooled Reactors). One of the technical issues raise by the development of the VHTR is the mixed convection, which occur when the driving forces of both forced and natural convection are of comparable magnitudes. It can be encountered as in channel of the stacked with fuel elements and a decay heat removal system and in VHTR. The mixed convection is not intermediate phenomena with natural convection and forced convection but independent complicated phenomena. Therefore, many researchers have been studied and some primary issues were propounded for phenomena mixed convection. This paper is to discuss some problems identified through reviewing the papers for mixed convection phenomena. And primary issues of mixed convection heat transfer were proposed respect to thermal hydraulic problems for VHTR. The VHTR thermal hydraulic study requires an indepth study of the mixed convection phenomena. In this study we reviewed the classical flow regime map of Metais and Eckert and derived further issues to be considered. The following issues were raised: (1) Buoyancy aided an opposed flows were not differentiated and plotted in a map. (2) Experimental results for UWT and UHF condition were also plotted in the same map without differentiation. (3) The buoyancy coefficient was not generalized for correlating with buoyancy coefficient. (4) The phenomenon analysis for laminarization and returbulization as buoyancy effects in turbulent mixed convection was not established. (5) The defining to transition in mixed convection regime was difficult.

  18. Some problems of free convection in a macrocapillary

    Energy Technology Data Exchange (ETDEWEB)

    Luikov, A V; Berkovsky, B M; Kolpashchikov, V L

    1971-01-01

    Solution is given to a number of problems of free convection in incompressible viscous fluid in elementary macrocapillaries with nonuniform temperature distribution at the boundary. The fluid flow structure and effect of a magnetic field on convection in the case of conducting fluid has been studied in detail. The influence of macrocapillary properties on the flow structure, rate of convection, and temperature distribution has been estimated.

  19. Convective Cold Pool Structure and Boundary Layer Recovery in DYNAMO

    Science.gov (United States)

    Savarin, A.; Chen, S. S.; Kerns, B. W.; Lee, C.; Jorgensen, D. P.

    2012-12-01

    One of the key factors controlling convective cloud systems in the Madden-Julian Oscillation (MJO) over the tropical Indian Ocean is the property of the atmospheric boundary layer. Convective downdrafts and precipitation from the cloud systems produce cold pools in the boundary layer, which can inhibit subsequent development of convection. The recovery time is the time it takes for the boundary layer to return to pre convective conditions. It may affect the variability of the convection on various time scales during the initiation of MJO. This study examines the convective cold pool structure and boundary layer recovery using the NOAA WP-3D aircraft observations, include the flight-level, Doppler radar, and GPS dropsonde data, collected during the Dynamics of MJO (DYNAMO) field campaign from November-December 2011. The depth and strength of convective cold pools are defined by the negative buoyancy, which can be computed from the dropsonde data. Convective downdraft can be affected by environmental water vapor due to entrainment. Mid-level dry air observed during the convectively suppressed phase of MJO seems to enhance convective downdraft, making the cold pools stronger and deeper. Recovery of the cold pools in the boundary layer is determined by the strength and depth of the cold pools and also the air-sea heat and moisture fluxes. Given that the water vapor and surface winds are distinct for the convectively active and suppressed phases of MJO over the Indian Ocean, the aircraft data are stratified by the two different large-scale regimes of MJO. Preliminary results show that the strength and depth of the cold pools are inversely correlated with the surrounding mid-level moisture. During the convectively suppressed phase, the recovery time is ~5-20 hours in relative weak wind condition with small air-sea fluxes. The recovery time is generally less than 6 hours during the active phase of MJO with moist mid-levels and stronger surface wind and air-sea fluxes.

  20. Strategic Repositioning for Convection Business Case Study: AR Vendor

    OpenAIRE

    Anindita, Pratisara Satwika; Toha, Mohamad

    2013-01-01

    The study aims to determine suitable position and strategy in order to reach superiority in convection business based on the company strengths and weaknesses. A study conducted in late 2012 at AR Vendor, a home-based convection company which focus on the t-shirt screen printing service. In response to the issue of the below average profit margin, the company has to rethink their position and strategy in handling the convection business environment. While AR Vendor business may growth in accor...